Only experience of the 330d, watch for warping discs done cheap.
Thermostats as stated, i had to put mine in sport down motorway to get temp up as power was down significantly. Stats weren't expensive (gates are genuine bmw ones), over an hour to do.
Wiper motors get gummed up with grease, half hour job, may need a replacement relay too.
front tca's and tie bars on rear wear, again not that expensive or time consuming.
That's the bad so far, tyre wear could be a problem....
Remapped and it does like to shake is arse lol!
Get as many toys as possible, xenon lights are a must, i drive and sat nav too.
Got to be an m sport too, so much nicer looking.