The Road Kill rules have been around for a bit, but they've not always had a set of minis that have been for the game. Now, JohnnyBorg Casting is running a Kickstarter campaign to fix that. These new cars are designed to be rather modular, so you can arm them as you want, and are in N scale.
More than just some cars and weapons, there are also terrain elements that have been unlocked as part of the Kickstarter. Also part of the campaign, you can get the Road Kill rules for free. Yup, all 98 pages worth. Just download them and check them out.
The campaign is 6x over their funding goal and still has 46 days left on the clock.