MM2 Central: www.mm2c.com
One of the best MM2 sites on the web. Full of info and all sorts of stuff.

Absolute Zero: www.absolutezero.cn.st
This site has many original cars not listed on the MM2C site. Check it out today!

Microsoft MM2: www.microsoft.com/games/mm2
General information on Midtown Madness 2. This is the official MM2 site.

Zone.com multiplayer: www.zone.com
Here is where you can play multiplayer. It's easy: just sign up for a free zone.com membership and you're set to go! Also plenty of general info and tips/tricks.

Zmodeler: www.zmodeler.com
This is where you can download the program to build your own MM2 cars. This is only recommended for serious users with some understanding of design.

Gravity Design: http://gravitydesign.cjb.net
This new site is all about the creation of new tracks for Midtown Madness 2.