Hei.
This is what I did on my Uno. First: Do not bolt the amp directly to the car so it touches the car's metal. This will cause a "hum" in your speakers due to grounding. Grounding should be done with the ground wire.
I used a piece of wood, about 1" thick, and applied some cloth to it. Then bolted the amp to it. This little installation was then added with something we call "patentbånd" see link http://www.sav.dk/produkter/isofix/sav_patentb%C3%A5nd.htm and attached to the seat's front brackets. This has worked for a year, and the the installation has never moved, jumped or whatsoever. Make sure the "patentbånd" doesn't touch the amp (if it does, use som insualtion) because it grounds itself. You want pictures?
Edit: This also makes it rather time-spending to steal aswell.
Morten.
abarth 14" wheels on good-year eagle ventura. abarth steering. inter-alloy 40 mm lowering. monroe sens-a-track shocks. phoenix gold audio. dalmatian refurnish.
projects: air intake. front seats. exhaust. rear tint.