I have a 530i and love it. there are very few differences between 2001 2002 and 2003. in 2001 there was a convenience package offered that had power passenger seat. This function was made standard on the 2002 year. That is pretty much the only difference in the years for the 530i. The 540i also has very few if any changes I think. I personally like the 530i, its pretty powerful and gets great gas milage. I have a manual transmision and get between 26 to 30 miles per gallon average, that is including city driving. Mainenance is free for the first 3 years 36K miles, this may have been bumped up to 4 year 50k in 2002 or 2003. Not exactly sure. Eiter way both 530 and 540 are awsome cars. There are very few problems with the car from what I have experienced and heard about. Little things like the cooling fan making a jet like noise, AC smelling after a while which can be fixed by spraying lysol disinfectent into the air conditioning intake. I have had some tire wear issues which seem to be somewhat normal as the camber is set such that the back insides of the tires wear more execively then the rest but that is done to improve handeling. overall a great car with very few mechanincal problems... Hope this helps.