MX-5 (NA (Miata / MX-5 / Eunos Roadster))

An American Idea Put to a Japanese Company

Bob Hall was a Californian motoring journalist, fluent in self-taught Japanese, whose father had run MGs, Triumphs and Austin-Healeys. Hagerty places the decisive conversation in 1978, when Hall was at AutoWeek and met Kenichi Yamamoto, then head of Mazda research and development, and suggested recasting the rear-drive 323 as a two-seat roadster. Yamamoto was noncommittal. In 1981 he asked Hall to study it properly; Hall joined Mazda's Californian research organization as a product planner and argued in an early-1982 position paper that recycling existing components was the only way to make the numbers work. The program ran off-line, and the American position was that it should be a front-engine, rear-drive roadster or nothing at all.

Duo 101, V705 and the Elan on the Bench

From 1983 the concept became an internal competition between the Californian studio and the Tokyo team. At the first judging in 1984 California's front-engine rear-drive proposal, Duo 101, beat Tokyo's front-drive and mid-engine alternatives, the mid-engine layout having struggled against noise and vibration targets. Mazda's own account confirms the reasoning: the linear responses of the original lightweight sports cars were judged unobtainable without rear drive, and a new powertrain accepted rather than compromise. A running prototype, V705, was completed by the British consultancy IAD in August 1985 with a fiberglass body over 323 mechanicals. Production approval brought the codename P729 and Toshihiko Hirai as chief engineer. Mark Jordan drew the exterior in California and Masao Yagi pushed the styling further towards the Lotus Elan; Tom Matano and Koichi Hayashi settled the detail once the project moved back to Japan. The Elan was not a vague influence, it was the reference object.

Jinba Ittai and the Power Plant Frame

Mazda's design principle was jinba ittai, horse and rider as one. The engineering that carries it is mostly unglamorous: double wishbones at all four corners, near-equal weight distribution, a five-speed gearbox lifted from the rear-drive 929/Luce with a very short throw, and an aluminum power plant frame bolting engine and gearbox rigidly to the differential housing so that driveline movement is taken out of the response. Mazda still calls the frame unique to its sports cars and essential to their directness, while conceding it is awkward to assemble on a mixed line. The car reached the United States as the Miata in May 1989 as a 1990 model, at a base price of $13,800, and Japan on 1 September 1989. Autocar recorded 9.1 seconds to 60 mph and 114 mph, called the gearshift the car's real advantage and scored it nine out of ten.

The 1994 Rebuild

For the 1994 model year the car was reworked around new side-impact legislation. The 1,839 cc BP-ZE arrived at 129 hp, rising to 133 hp for 1996; brakes grew, and the shell was braced, most visibly by a track bar between the seatbelt towers but also through both subframes. Dual airbags went into a redesigned dashboard. The car gained weight and, on the published figures, very little speed. In some markets, Europe among them, the 1.6 was kept on below the 1.8 as the cheap option in reduced-output form, by how much is genuinely unsettled, with published figures ranging from 89 hp to 110 hp.

Three Names and the End of the Run

In Japan the car was sold as the Eunos Roadster, Eunos being a separate premium channel Mazda was building in the manner of Acura or Lexus; in North America it was the Mazda Miata, elsewhere the MX-5. Japanese specials came thick and fast, along with M2 Corporation's low-volume conversions, and Britain received a long series of named editions ending with the Berkeley in 1998. The American price climbed from $13,800 at launch to $19,125 for the last 1997 cars. Mainstream production closed in 1997, replaced by the NB, which kept the layout and dropped the pop-up headlamps.

Two faults decide what an NA Miata is worth. The first is rust: rocker panels, rear arches and floors, developing from the inside, expensive to put right properly and frequently disguised. LucaCarMods, a restoration specialist, explains the mechanism: the rockers are double-skinned and spot-welded, trapped moisture cannot escape, and a proper repair means cutting back to sound metal, zinc coating and welding in new steel. Owner-reported costs on the Grassroots Motorsports forum run from $370 for rust cut out and fresh metal let in at a local shop to under $1,000 for both rockers done in primer, with worse cars quoted high enough that a better shell becomes the cheaper route. The second is the short-nose crankshaft on early 1.6 engines. Miata.net puts the keyway engagement area at 0.045 square inches against 0.087 on the long-nose part, notes that the timing cog acts as a structural member so the small pulley bolt carries both timing and accessory belt loads, and records the change to the large-bolt big-nose crankshaft at US VIN 209447 during 1991. Hagerty reckons it reached about 1 percent of 1990 and early 1991 owners, usually after the pulley key was reassembled wrong at a timing belt service. Worn keyways are not repairable; the fix is a later crankshaft assembly, which on a big-nose conversion also means the oil pump and possibly the front cover. Away from those two the mechanical package is durable, with Hagerty UK reporting serviced examples past 124,000 miles. The recurring smaller faults are a silted radiator causing head gasket failure, a rattle on start-up from the hydraulic tappets, rear calipers sticking on cars that sit, and soft tops that cloud and split.

Structure first. The rocker panels are double-skinned and spot-welded and corrode from the inside, where trapped moisture cannot escape, so a clean-looking rocker proves very little. Hagerty's US guide calls them notorious for rust, worst ahead of the rear wheel arches, and warns that body drains plug up and back water into the cabin, taking the floors with the carpets. Hagerty's UK guide ranks the bottoms of the rear fenders ahead of the wheels as the worst area, because moisture sits behind the panel, followed by inner and outer rear arches, floorpans, the bases and tops of the front fenders and the feet of the windshield pillars. Classic & Sports Car adds that rockers are rarely repaired properly and that clear drain channels are the best available proxy for an attentive owner. Panels welded over existing rust are common and leave the corrosion running underneath. Then the crankshaft. On early 1.6 cars the pulley nose is short and the small pulley bolt carries both timing and accessory loads; the MX-5 Owners Club identifies the short-nose crank by four slots in the pulley against eight on the later part. Look for a wobbling pulley, ferrous powder around the bolt or key, a bent or rusted key, and an engine running poorly because the timing has crept. Beyond that, check the radiator is not silted; check the top for clouding and rot; check the rear calipers on a car that has stood. Twenty-five-year import rules have put Japanese-market Eunos Roadsters on American roads alongside home-market Miatas, so establish origin from the rear license plate recess, square on a Eunos and rectangular on a European car, and from the VIN prefix, JM1 North American, JMZ European, JM0 Australian, with Eunos cars carrying a shorter Japanese chassis number instead.

As of September 2026, classic.com's NA sub-markets separate more usefully than any single aggregate figure. Across the generation the benchmark sits at $12,255, with the lowest recorded sale at $1,450 for a 1995 Eunos-badged import in December 2021. The base model sits below that at an $11,138 benchmark and an $11,183 average on a rising trend, its lowest recorded result $2,475 in April 2022, and current asking prices spread from $9,500 to $30,500, a much wider band than the sales data supports. The M-Edition is the strongest sub-market, at a $15,218 benchmark and a $14,807 average, also rising, over results running from $3,500 in October 2023 to $24,250 in September 2026. Two sub-markets trend the other way on very thin evidence: the 1993 Limited Edition at a $12,611 benchmark against a $13,011 average across three comparable sales, between $7,025 in August 2023 and $13,000 in March 2026, and the R-Package at a $12,640 benchmark against a $13,098 average across four, between $7,000 in October 2022 and $14,500 in May 2026. A sub-market counted in single-digit sales moves on one car, so those downward arrows say considerably less than the base model's upward one.