Modeling question

I'm looking to get into car modeling. I just have some question though. If i bought this model: http://us.st2.yimg.com/store6.yimg.com/I/matrixcollectibles_1741_53200527 would I just add these rims: which are also made my Fujimi?
http://www.tinyimports.com/model_kits/Accessories/Rims_Mufflers_etc/fuj19219_tc-005.GIF and how does lowering the car and adding bigger mufflers work?

Technically, you can use any rim on any car, even if the scale is out of size (at least to a reasonable degree). You'll have to do conversions from male to female or vice-versa depending on the situation.