you could get a sensor for your car that's made for convertibles, if it detects movement it'll go off. i always park far away from everything, even though my car looks sorta bad right now (no dents though ).
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15
). 