I just got a new Audi A4 as a company car and it has an SD card slot in the stereo. I found it wouldn't work with a spare SDHC card I had, but works OK with an old 256mB SD card from my missus' old camera. I've just ordered a small selection of 2gB and 4gB cards (only came to £14 inc del from Memorybits) so I'll post back links to which ones work, the others can be use in her new camera anyway. I got 5 albums on the 256mB at 129k rate (good enough in the car I suppose) so should be around 40 albums on the 2gB, maybe a bit less if I up the bitrate. Hopefully be useful info for other members who may come across this thread.