With digital cameras everywhere and no cost to use, I would say take a thousand pictures,maybe even some video.
And think how much wiser your son is, great isn't it?
I am 530 shopping 01-02 and passing my 150k fine 99 323 to my freshman EXCUSE ME
SOPHOMORE son, I don't expect the car to really survive indefinately, just as long as he does.
The old subs died the first week. Yesterday I was in a guys garage picking up 4 sport springs I had paid him $60 for from e46 fanatics forum, and dam if he didn't hold something and ask me, how are the subs on your 99? sold for $40 with amp. Crazy
Anyway remember to replace everything u can afford that is hard to get to, like shifter bushings if manual, engine mounts etc
take the hood off completely, watch the paint be careful
good luck sorry for rambling,