According to the google translator you are wanting with adding map files to MM2. I'll try my best to help you, heres how:
Download a map from
Tracks Section that you want.
Once downloaded you need to extract the file. You'll need
WinRAR to do so if you don't have it.
Open the file you downloaded with WinRAR, theres a ".ar" file inside. Drag it to your MM2 folder directory, in this case "C:\Program Files\Microsoft Games\Midtown Madness 2".
Start the game, select the map you downloaded, and enjoy.
Hope this helped bud'.