Lol, this has absolutely nothing to do with suspension, braking or tyres!
If cops have a reason to remember you, then they will regardless of custom plates or not. They now have this new fangdangled thing called a computer installed in all their cars, which your plates (custom or standard) can be punched into and all your details come up for them to see if they should be pulling you over or not.
If you wanna get custom plates, just do it, there are a LOT of skylines getting around SA with custom plates - most of the them without defect stickers. lol.