Isetta (Isetta 250 / 300 and BMW 600)

Milan, Not Munich

The Isetta was Italian before it was German. Renzo Rivolta had built refrigerators, then motorcycles and scooters, at Iso in Bresso north of Milan, and he set the engineers Ermenegildo Preti and Pierluigi Raggi on the problem of a vehicle small enough to be cheap and useful enough to be a car. What they produced was an egg on four wheels, about 7 feet 6 inches (2.29 meters) long, entered through a single front-hinged door that carried the steering column out with it, its rear wheels close enough together that no differential was needed. Accounts of the launch differ - Wikipedia dates the introduction to November 1953, BMW Blog to the Turin show of 1952 - but the outcome does not. Around a thousand were built. Rivolta's better idea was to sell the license abroad, to Velam in France, Romi in Brazil, De Carlo in Argentina, a British concern and BMW.

The License and the Motorcycle Engine

BMW in 1954 was in serious trouble: the 501 V8 was not selling, much of the pre-war manufacturing base lay behind the inner German border, and Goodwood's account has a Glas takeover looking plausible. BMW took its license from Iso that year - its press office places the agreement at the Geneva show, Wikipedia says mid-1954 and adds that BMW bought the complete body tooling as well as the rights. The decisive change was under the tail: out went Iso's two-stroke, in went the air-cooled four-stroke single from the R25 motorcycle, 247 cc and 12 hp. That made it a BMW in the only sense that mattered to a Munich accountant.

250, 300 and the Windows

The 250 sold immediately: BMW Group Classic records more than ten thousand in the first year, BMW's press office 12,911, and BMW Blog car number 10,000 on 20 November 1955. Then German licensing law moved, and BMW answered with a 297 cc engine giving 13 hp at 5,200 rpm - more torque rather than more speed, since the quoted 53 mph did not change. From October 1956 the bubble windows gave way to sliding side windows on the Moto Coupe DeLuxe, and from 1957 an Export specification added a fixed roof, a revised chassis and optional right-hand drive. The peak year was 1957, near forty thousand cars.

Brighton, and the Third Wheel

British production began on 23 April 1957 at the former Brighton Locomotive Works, taken on by Dunsfold Tools Ltd and later renamed Isetta of Great Britain. The site had no road access, only a flight of steps, so cars left by rail, three to a wagon; engines, transmissions and Bavarian-pressed panels arrived the same way each Saturday. The first thousand were left-hand-drive four-wheelers for Canada. Three-wheelers followed from 1959, because a three-wheeled vehicle attracted lower British tax and could be driven on a motorcycle license, and right-hand-drive cars needed a 60 lb counterweight on the left.

The 600, and What It Bought BMW

The 600 of 1957 stretched the wheelbase to 66.9 in (1,700 mm), widened the rear track, added a second door on the right and fitted the 582 cc flat-twin from the R67. Lane Motor Museum records a United States price of $1,398 for it. More significantly, it carried BMW's first semi-trailing arm rear suspension, which the company then used on almost every car it built until the 1990s. It did not sell: Below the Radar records BMW borrowing seven million marks against hopes of 400,000 cars a year, and the 600 pushing it further into the red instead. What it did was provide the platform stretched into the 700, which sold 188,121 examples and carried BMW to the Neue Klasse.

The single-cylinder engine is simple and rebuildable, but the crankshaft and aluminum connecting-rod assembly is the known weak point and breaks; steel replacements are the usual remedy, and microcar.org treats this as expected rather than exceptional. Push-rod tube seals leak at both head and block, and the o-ring seals between the suspension casting and the swing arms leak so consistently that dry ones are the surprise. There is no oil filter, so oil changes are frequent and a hundred-mile change after a rebuild is standard. Overheating follows a failed cooling fan and destroys the engine quickly. Brakes are the other recurring theme: wheel cylinders freeze on cars that have stood, leaking fluid contaminates the linings, and previous owners have fitted non-original master cylinders that complicate repair. Transmission linkage bushes wear. Corrosion concentrates in the wheel arches and the battery box, and after fifty years most fasteners are seized. Parts supply in the United States is better than the size of the car suggests: microcar.org's directory lists American suppliers for the consumable end of a rebuild, with stainless brake hoses quoted at $25 each from Bavarian Autosport, a steering damper at around $16, correct 4.80 x 10 tires from Coker and a replacement windshield at just under $300 before crating and shipping, alongside named specialists for engine, transmission, chain-drive and brake-cylinder work.

Establish which car is in front of you first. A 250 and a 300 are not the same object to the market, the bubble-window and the October 1956 sliding-window cars are visually distinct, and a Brighton-built three-wheeler is a different vehicle again - the Dare to Dream result shows how far a documented British car can separate from the benchmark. Chassis and engine numbers should be legible and agree with the paperwork. Steel is the main worry: wheel arches suffer, particularly on cars that saw British winters, and the battery box corrodes on almost everything. Because the whole front is one hinged door, check that it shuts and seals evenly and that neither the hinge nor the articulating steering column has been shimmed to disguise a sagging shell. Check the fabric sunroof works: it is the emergency exit, not a luxury. Underneath, look at the chain case for leaks and at the o-ring seals between the suspension castings and the swing arms. On a 600, the second door and rear seat area rot unseen, and an invoice file matters: the Monterey car that made $73,920 carried over a hundred invoices and close to $70,000 of work, and the $27,500 Hershey Isetta nearly $6,000 of mechanical work alone.

As of September 2026 classic.com's benchmark for the BMW Isetta line stands at $31,450, with eleven cars listed for sale, a recorded low of $7,000 (a 1957 car, 3 February 2024) and a high of $56,500 asked for a 1957 car in Medina, Ohio. The line splits by variant, and as of September 2026 all three sub-markets read downward: $20,966 for the 250 on an average sale of $24,229, $30,852 for the 300 on an average sale of $31,289, and $32,073 for the 600 on an average sale of $34,967. The 300 is the liquid part of the market, with three results in the six weeks to mid-August 2026 at $37,000 (a 1956 car, 28 July), $34,250 (a 1957 car, 4 August) and $30,800 (a 1958 car sold by Broad Arrow in Monterey County, 14 August). Hagerty's Isetta market piece, read in September 2026, works in condition grades rather than benchmarks: a median of $38,500 for a #2 Excellent car against a January 2017 peak of $44,500, about $29,300 for a #3 Good 300 of 1957-62, and the high $25,000s for a #3 250. Auction evidence brackets that band. RM Sotheby's sold a 1957 Isetta 300, chassis 570827, for $27,500 hammer at Hershey on 9-10 October 2024, and a Brighton-built car in Team Brecht livery, chassis A 11752, for $58,800 at Dare to Dream in Toronto on 31 May - 1 June 2024. A three-wheeled 1959 Export car made $40,250 at the Bruce Weiner Microcar Museum sale in February 2013, and a restored 1959 BMW 600 made $73,920 at RM Sotheby's Monterey in August 2024.