i have a 4th gen. i was wondering where you found a good ground for your amp.

Rear strut tower.

Seatbolt bolt under the rear seats...

/thead

in the spare tire well.

i found some nice metal spot behind the vents and down a bit....

I used the bolt next to my jack

i'm using a bolt under the seat.

x 2

same here.

I have a 5th gen, but I mounted my amp under the driver's seat and grounded it to using the front bolt of the seat.

That's how I did mine too. Works great!

On my 3rd gen I used a bolt at the trunk latch.

same

... to metal. lol.

nah, but really, *technically* your not supposed to use factory bolts. You're supposed to drill directly into the chassis of the car. Avoid parts that are welded onto the chassis (like cross beams or parts of seats, trunk, door, etc) because lots of times they are held together by glue, rather than good conductive bonds. The reasoning against factory bolts is that they are designed to secure and hold things, not transfer current. in reality, they work, but 'pro' installers generally avoid using factory bolts.

That's what Don did for me. Drilled right into the chassi. Works great