Cake request number 2! : )

I've been asked to do another birthday cake this time for a lad that's going to be 18. The request from his mum is for a car shape, preferably a sporty car, red and white because he likes Man U and...... I have no idea where to start!
I've googled "sports cars" and "car cakes" and I'm thinking......

.....something like this as a starting point maybe?!?
I also searched for car shaped cake tins seeing as I am still new to all this and could use the pre-made help but all I could find is:

I think it's just too box shaped to work with but maybe I could use it as a base to sculpt from?? Any suggestions/advice would be helpful right now, I'm off to cake dec class later to ask Linda (my teacher) for help : )