It may seem stupid that I am submitting an entry to a competition that I also started, but I'm not, and this one won't be counted. This is just a demonstration of an entry that fits all the criteria.
Powered by a 'V4' (the same one that was in that couch) which I boosted to around 180 hp. Top speed is around 130-140 mph (but it could go faster if it was lighter, which was prohibited by the rules). In did not say this was a good demo though...
I mean, it looks nice, but the engine becomes a little unstable at high rpm or under a heavy load
On this thing's FIRST EVER run, I managed to get it through in 8 minutes and 6 seconds, average speed 69.0412 mph (or 111.11 kph if you use Metric

)
If you haven't seen my contest yet, it is here:
http://www.algodoo.com/al … p?id=99648