I'm working on a modest upgrade to the stock system in my 2010 A4, but despite loads of great reading here I am still a bit confused with leads. I have replaced the tupperware sub on the rear shelf with a JL 10", and now am looking to replace the amp in the rear cubby hole in the boot. I'm not planning to replace the HU (concert non bose). Is there a lead that jsut converts the current plug into the rear stock amp to allow wiring to an aftermarket amp fitted in the same place without hacking the original wiring to bits ? I believe I would still need power feed for the upgraded amp, but that's no bother as the battery is in the boot. Many thanks.