i have concrete sloped driveway from street level down to the cellar level--my car bottom scrapes at the top of the driveway and at the bottom of the driveway going into the garage. here are the dimensions:
the vertical drop is 5ft 3in and the horizontal run is 21 ft.
the slope is abaout 26% in one slope--no break over points except at top where the driveway meets the sidewalk and at the bottom where is joins the flat level floor of the cellar garage...help!
You might be able to fix the problem with some strategically placed humps in the driveway. Drive very slowly down the driveway, and when the middle of the car scrapes at the top stop. Mark the driveway where your front wheels are. If you put a hump there just a couple inches tall, and a foot or so long, I'll bet you won't scrape anymore.
The tail-drag at the bottom is harder to fix. You'd probably have to ease the slope at the bottom, by filling it in a bit.
Might be cheaper to see if your car can take a larger tire size.