The guys at Victory Lap Hobbies have this neat article on some modifications to the Scalextric Mercury Cougar to improve its appearance which you'd probably like reading, since it can possibly apply to your APC car even if its not a Cougar:
How They Should Have Made It – Recent Scalextric TransAm Cars – Part 1, Mercury Cougar
Bear in mind that while the front tyre and body modifications are legal for our APC class, the magnet location must comply with our rules.