1973 Austin MINI 1.3L Petrol · ABW 153M

Auto Express sums it up: all Minis rust, often spectacularly, with A-pillars, scuttle panels, sills, floorpans and the front subframe mounting points the prime suspects, plus corroding shock-absorber mounts and a rear subframe that is a common MoT failure. British Classic Cars adds the A-panel where the wing meets the door, the boot floor and battery box, and the subframes' mounting points as structural items, while the Bull Motif specialists note corrosion starts between panels, behind seam sealer and inside box sections, with a rusty outer sill often just the visible skin of a failed inner sill and floor flange. Poor repairs hide behind fresh underseal, so inspection means lifting carpets, removing boot boards and tapping with a hammer.

The Mini's genius — gearbox in the engine sump — is also the transmission's Achilles heel, because whatever wears the oil wears the 'box. British Classic Cars calls worn synchromesh or a rattly gearbox common but rebuildable, and the most fragile mechanical part of the car; SYP Mechanic adds that a little whine is normal but hissing means worn bearings, and notes jumping out of gear and worn CV joints as the tell-tales. Auto Express is practical about it: a standard four-speed can run beyond 100,000 miles before a rebuild if the shared oil is changed every 3,000 miles — a cheap insurance most project cars have never had. A hissing, clashing box turns a dream classic into a £800-£1,500 rebuild job, so cold starts from a cold gearbox on a test drive tell the truth.

The A-series is famous for longevity — around 100,000 miles before rebuild when serviced, says Auto Express — but it leaks as standard and dies from the classic combinations. SYP Mechanic lists rocker cover, driveshaft and gear selector rod leak points, blue smoke on start-up from worn guides, seals, rings or bores, and creamy emulsion under the oil filler as the head-gasket warning, while 1275cc engines wear valve guides faster. Auto Express flags the noisy timing chain on Mini 1000 cars as a duplex-chain upgrade job. Everything here is cheap relative to other classics — the body, not the engine, decides the budget — but a rebuilt A-series is a real cost at £1,500-£3,000, so check the cap and the coolant on every viewing.