Seriously?
http://www.voobly.com/There's an MTM2 Lobby there, can play online with each other in Voobly lobby/client, just make an account there, download the client, with the game browser find Monster Truck Madness 2; if it's not listed on the right, go to "Games", and look for Monster Truck Madness 2. If not understand how to do that, in Game Browser hit "All Games" and scroll down until you see the CD-ROM ones and Monster Truck Madness 2; click it and "Scenic Route", then "Open The Lobby".
As for the networking, just in your router, make a DHCP reservation for your MAC address to keep your current IP address (since u so smart I'm sure you know how to do this), and forward the ports MTM2 needs (47624 tcp, 6073 udp, 2300-2400 tcp & 2300-2400 udp), OR if you don't want to make a DHCP reservation, just go to your network adapter and make your IP address static instead of dynamic, meaning manually set the IP address to the one you forward the ports to, and the IP will never change therefore you won't have to worry about the MTM2 networking. Sure this might be a 'slight' security vulnerability..but you aren't worried about getting hacked are your? Anyways, there's your answer.
The problem is now there's less than 6-8 people that play, when more should be getting back. This pic below was taken in 2013.
This was in 2013:
https://i.imgur.com/8KBujlD.pngThere's your "MTM2 Lobby" Have a nice day =)
More people should get back into it and be havin' some fun. We play at 9pm, est, every sunday. Probably for a good 2 hours at least, sometimes up to 3-4 hours.
9pm, eastern, every Sunday.