If it has a full service history, by which I mean invoices, not just a stamped book then you should be fine.
It's not essential for it to be a main dealer history, which will increase the asking price, but you want it to have been looked after by someone who knows the model.
Not just some backstreet bloke who's been servicing cars for five million years and still swears by Castrol GTX.
You can really apply the same rules as when buying any used car.
The Z3 is an elegantly simple car, there's nothing too sophisticated on there that's likely to cause problems as it's all tried and tested technology.
I wouldn't set too much store by mileage - buy a genuine 130,000 miler at the correct price rather than a questionable 40,000 miler with a patchy history.
Any car who's history cannot be proven and backed up by documents MUST be treated as a high mileage example. As such, buy if the price is right and you want the car.
One question: Are you sure you want to muck about with the smaller engined ones - the 1.9 early one is only about 118bhp. It's not that they're slow as such, but for me a two seater no roofer should have more clout.
The 2.0 litre unit is 150bhp which is more like it.
If it were me I'd never be happy knowing that someone else had the 3.3, which sounds and goes like it's looks suggest that it should.
