The new Boxster – the famous two-seat roadster first launched by Porsche in 1997 — and its mid-engine coupe sibling, the Cayman — which debuted in 2006 — offer more powerful flat-six boxer engines, which are even more fuel efficient than the powerplants they replace

The S model isn't really designed to compete against the Ms, but Top Gear makes it clear that they really aren't competitors at all. The Porsche Boxster S is very well-mannered, but the M Roadster is most fun when you let it hang a bit loose.