A black on black car in general doesn't get more than 15 degrees hotter than a white with tan interior. Tint your black car (It'll look way better, and where I live it's a must anyway (Tucson, AZ)) and you're right back down (or even cooler inside) than a white with tan car. It all comes down personal preference. If you love black on black, don't let 7-15 degrees deter you from getting the look you love. I've seen some people (like Grandmas, not contractors) driving around Tucson with leather Home Depot work gloves on. If they tinted their car like I do mine, you can keep the work gloves in the garage. I've never been overly hot with my car tinted to the darkest legal setting in AZ. Actually, not even darkest. Darkest legal up front, and one shade darker (not Limo) in the rear.