Well, electric cars are much simpler...
... and Dyson already has experience with many of the remaining hard parts. They know to design 3-dimensional parts, they know about fluid dynamics, they know about electric motors and batteries.
So my guess is that they'll just have a motor per wheel connected to some dampers. I mean there are student competitions for building cars, it can't be _that_ hard.
Also Dyson is to big to have to worry about regulatory issues.