I know that some of the French quadricycle's can do more than 50mph, but I have no idea what the actual rules governing their access to motorways are. Presumably if a 48mph Renault twizy can go on a motorway, so should a 50+mph Aixam?. Unless it is also to do with the weight of the vehicle?.

I have looked at them in the past, and thought they would make a good city/town runaround. But at the end of the day, they are not very good value, they are not that economical, and they don't have to do that Euro ncap crash test (and I don't fancy having an accident in one). As a runaround, a C1/108/aygo make a lot more sense to me.