To install the wheels:

Run TXD Tool. (You can get it from www.gta3hq.com).
Open the MISC.TXD file in the "[gta3 dir]\models" folder.
Find where it says wheel_saloon64 and highlight it by clicking on it.
Click "Commands>Import>Texture"
Import wheel_saloon64.bmp from this zip file.

That's it!