Val it was a 55 plate Boxster S, so I assume it is the new model?
ps the A41 is a great road especially from Watford out towards Tring & Aylesbury. Theres a section before Aylesbury I think which is newly laid 3 miles approx absoloute flat & straight. It cuts across what used to be farm land & makes the journey shorter by a bit, with no exits, slip roads, bridges etc, ideal for driving ......below the speed limit!!
Only thing is its not on most GPS units as newly laid, so just follow A41 straight & disregard GPS.