If I owned a 1999 Taurus it would already have several holes drilled and look like a porcupine. All kidding aside, you'd be much better off with a good quality NMO mounted VHF antenna.
HF? While I agree about the reluctance of mounting some of the heavier screwdriver antennas on ballmounts, it is somewhat more efficient than mounting the antenna as low as you suggest.
You might want to look at HiQ antenns web site. It takes some searching around, but you'll find a number of pictures showing their mounts. At lease it'll give you an idea or two.
If you're into auto-couplers, you might want to look at my web site for some ideas.