Heynow999 offers a good suggestion. I always see lowered cars take speed bumps and driveways at an angle. Speed bumps are handled with a zigzag pattern...moving to the leftmost area of the lane, cutting sharply to the right across the bump, and straightening out in the rightmost area of the lane.
I'd lose the antenna. I'd bet you'd decrease air drag a healthy fraction of a percent.
- LostCause