I like the cycle car idea Rob, but remember that two engines are illegal for road use. 2 or more electrics are legal but not IC engines.
You could join two engines together and make a quickly twin, thats legal.
I was stuck behind a quickly on the coast 2 coast run last month for quite a few miles, only because I was lost and had to follow the guy, it was painfully slow, 25mph max, maybe it was not running right or the rider weighed a lot but I couldnt wait for the next batch of riders to fly past so that I could tuck in behind them. I think a quickly motor in a cycle car would barely move from the spot!
Best bolt some together excelsior fashion!
Right, Must remember to bring Robs quickly parts and Stuarts AC transmission box, Bobette will be along next year if all goes well.