I have just been through the gauntlet of buying a mk 2 gti, my advice is look at plenty then buy one that has no rust on the body and structure, people will say that it's inevitable for them to be rusty, it isn't. And there are plenty that are solid, running gear is replaceable as are most other stuff but a rotten golf is bad news. Mine was a none runner but remarkably rust free I paid £700 for it h reg 16v loads of history, it needed a front subframe and some other stuff for the mot but crucially no welding. Parts are cheap front subframe complete with anti roll bar suspension arms £40, rear axles £40. The oily bits are cheap as well engines are £250+ interiors £150+. So a cheap car to own and upgrade, way nicer to drive than a mini and more reliable too. This forum is brilliant, good luck. Martin.
