Hi,
The cup is only a fraction quicker in a straight line. The most my brother has ever beat my mk2 by, in his clio cup, is a car length, side by side(normally it is half that). If I am behind him I can stay with him due to the slip stream effect, it is only through the corners that he has the advantage, however you can take out the spare wheel and take away the cups biggest single weight saving advantage over you, but that is getting anal.
Personally speaking, in a year to a year and a halfs time, you will use your car as just a means from getting you to a to b and the novelty of speed will have worn off, and you will not be so boy racery anymore. You will be glad you have climate pack and abs over a minimal speed advantage and a less noisy cabin and above all better residual value than a cup, once MOST the novelty has worn off and blieve me it will!
Remember the majority of buyers are not enthusiasts, are sensible, will look for the above ergonomics/economies and will steer clear of the cup as a result ON THE WHOLE. Try to look at the big picture, as the cup does not have the performance advantage renault would like you to believe, as I have never been soundly beaten by a cup on many occasion now, even thpugh they are great cars
Bye Bye