I don't know about the roof one... If you are thrashing it in a paddock you wouldn't want to roll it. We've had the pulsar up on 2 wheels numerous times, many close to tipping when its wet and digs in to the ground!
My KE70 wagon takes exceptionally well to slides through my paddock, very easy to control, so this baby shouldn't be too much different!
If the engine is bad, don't try and do burnouts on oil patches up on the road like we did. Its like 20 thrash sessions at once. My spare parts RA23 now sounds like it has a few coins rattleing around down in the bottom end, and can't rev above 3k on grass!