the cars we seem to be selling a lot of at the moment are 04-06 fiestas
02-06 corsas/03-06 focus/05ish bmw 1 series/merc b class.
these are the things that seem to be constantly going out.....
i would avoid 2.0 turbo diesel audi/vw as we seem to be getting constant issues with heater plugs/throttle bodies/injectors amongst other things.