Bonjour!
I can't comment on the technicals too much other than saying I would assume that the wheelbase for the 4.8 Plus 8 is likely to be identical to the Aero 8 as the chassis is the same. In terms of being 'bumpy'..... I don't think so. The car is stiff, but stiff in a good way, in a way that a performance car is stiff. I doesn't wallow like a Range Rover might, it's a direct drive experience. On major roads it's as smooth as silk - on lovely French roads it will be a dream.
The suspension has, I believe, changed very slightly between the 4.8 Plus 8 I have (2015 car) and the new Aero 8. Some say they can feel no difference, others claim it's improved.
My advice would be to buy one. I love mine.
