I'm pretty much a newbie to cars so take pity upon me. I just want to be sure but do the stock 03 cl-s rims fit on a 01 cl-s?

 

Yes any CLS 17"x7" rim will fit on any 01, 02, or 03 CLS year. TLS rims which are 17"x6.5" will also work. The non-S CLs and TLs are 16" rims.
I have 2 sets of 03 CLS 17x7" rims, one chromed, one stock, I'm gonna put on ebay soon.
Let me know by email if you are interested.