Sometimes in newer cars the metal under the dash is attached with plastic clips and does not provide a good ground at all. Sometimes they add grounding straps but the rest of the dash components are using that path and may cause some problems. I would mount a ground that is isolated of any other ground leads, at least a few inches and make sure that you scrape down to bare metal before fastening.

I had a amp under my back seat one time in my Datsun and every time I turned on the lights, used a turn signal and used the brake pedal at he same time my amp protection cut in or it blew a fuse. The ground spot I chose was even a few feet from the rear light harness ground strap. I had a theory that the body was getting enough of a "buzz" that it may be feeding back through the amp ground and causing problems. I moved the amp ground by adding a 6' lead and grounded it closer to the battery and had no problems afterwords.


Sean in NC