I think that for a feature Top Gear should invite the whole F1 grid to do a kart race on the test track;
Vettel, Kimi, Hamilton, JB and I reckon Ricciardo would be up for it, and then TG could prepare a load of TKMs in exactly the same manor, with each engine tested on the dyno to ensure equality.
I may have gone on a bit, but I would really like TG to do that.