All of them now are kinda high-mileage, so proper maintenance is of an utmost concern. Hopefully the timing belt(s) have be replaced, radiator has been replaced, the thermostat housing is replaced...all I can think of right now.
BMWs love brakes, so be prepared for that..rotors and pads.
The big motor is really, really fun, but for her, the smaller motor is probably better.
Get one in dark green with the black and brown interior...delicious.