i had one of those in my 93. it worked pretty well, but i dont think it was amplified like the one in that link. it worked pretty well, but not as good as a standard antenna. an amplified one might be worth it.
JUST AN FYI,
I wouldnt put that outside the vehicle. when i did mine, i just left the antenna base for the factory antenna there...and mounted this on the top/right of the windshield, inside the vehicle. hope this helps your decision.