Wheels made before Apr 06 need to be replaced, there's a thread on here somewhere. These are prone to flaking and cracking at high speed.
The garage will look at you funny and then after checking the computer will offer to check. The wheels have a date marked on the back of one of the spokes in a series of dots.
Also check the Z shaped floor fastener in the boot isn't broken, some people have complained about this.
Paint is a issue as mention above.
Tyres are as above, although swopping front to back can make all 4 last for 10 to 12 K, depending on your driving. Although driving in dolomittes reduces there life dramatically
You may want to upgrade bulbs in headlights as originals aren't great, but Mike can sort you out some decent bulbs.
Having said all that i and my wife use both cars every day and have both just returned from the 50 mountain pass dolomitte challenge. (3009 miles). We have had no major mechanical or electrical problems. Julie's used some coolant but on speaking with the dealer these cars can
When your on the test drive just take time to see how everyone arround you is reacting, this is one special car.
Although don't be affraid to walk away if the deals not right, some of these cars have been moved from garage to garage in a bid to sell them. A search on mini cherished will show you whats on offer and don't forget the ins group and tax band.
Sorry to go on but you won't reget buying one of these, so just take your time getting the price right.