KarBOOM 0.3 is on the way
This video demonstrates the different surfaces that will be available in the upcoming level editor: dirt, ice, tar, pits, and grass (which, of course, cars are severely allergic to).
Other working features (not shown due to their extreme ugliness at this stage of development) include conveyor-accelerated ramps, bridges, barriers and platforms.
As always, this will be free for download and offline play. Online play requires a premium account at KarBOOM.net, which is normally $5 USD, but there are still some free upgrades available on a first-come first-served basis.
The latest public version (0.2.4) can be downloaded at KarBOOM's downloads page here on IndieDB/ModDB.
Thanks to Ben Smart, my youngest brother, for regularly testing it with me and driving the orange car in this video.