This cap is pretty much useless as most ppl above have already stated, but YES: to answer your question - The Cap's Ground should be a GOOD GROUND - NOT just ran over to one of your amp case / mounting screw / bolts ! EVERY ground in ANY vehicle SHOULD be treated the SAME WAY - Use the SAME GAUGE wire as you do for the positive side of whatever you are grounding, and ground to a good SOLID, UN-PAINTED, METAL SURFACE... I always ground directly to the frame, or if uni-body: Run a dedicated ground from the battery along with your power wire when you run it. Honestly though: If you have yet to do the BIG 3 upgrade under the hood of your vehicle yet: DO IT - That alone will do more for you than that cap EVER will //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif GL, hope you get it sorted out