This car with his 0.30 cx, is an exemplar of aerodynamism surpassing many sport cars until today but when I look under it, I'm not impressed... I'm thinking for some time now since I saw the car jacked last time if the rear bumper cover is acting like a parachute. Lot of air circulating under the car may be kept by this big opening pointing at the front of vehicule... I'm wondering if I put some kind of plastic splash guard (like the one of the front) to close this hole between spare tire well and bumper cover cannot help against a potential parachute effect. My project is to put a spare front splash guard on to the rear as it have already the round shape (but I will need to cut it for exhaust). How it will be held is not clear from now. Anyone have tryed something there ? Images are for exemple as they are for an other car and it's a near perfect system. Some say on the net that it's help the car stick on the road at high speeds and the most important part in that system is the rear one. At least, if I can save MPG, I will be happy.