A decent Ground in that car is the bolt/rod that holds down that spare tire.take the tire out.sand down the metal/paint off, put a washer on, then the ground wire with a ring terminal,then another washer,and use a nut to bolt that joker down, and then you still have access to your spare tire in and out without worrying about the ground wiring coming loose, or taking it loose ect.I do this /have done in almost every car Ive owned with a spare tire well..seems to be a perfect ground every time for me/ never any issues.
