Just noticed this and have to agree with above, its a quick little motor, but my only comparison in small and fast is the Corsa VXR and this was no match in terms of fun, and if I'm honest the corsa plastic didnt feel that much worse. Interior is no match for BMW, but I guess the 1 series is a bigger car, but interior is far superior to the S1.
My kids hated it, they are 10 and said the back felt more cramped than the Corsa VXR, and given the price tag I could never justify the 30% more over the cost of comparable hot hatches.
I think the S1 badge is actually out of place on this car, its a very poor interpretation of an 'S' car.