So it seems like the greater majority of the people here are from the UK? So this may be of limited use as I don't know whether this holds true for right hand drive models. The amp on the right side is for the main speakers in the HK system, and the amp on the left is the Subwoofer amp. I replaced the factory Blaupunkt cd player with an aftermarket unit and got nothing. Next up is sourcing and installing a new amplifier unless I can find a used one somewhere. I'm not really all that picky about sound quality in a roadster, but I do like some sound, so this really sucks. I don't expect to find an HK amplifier for any decent price. This car is something my wife tolerates because I didn't spend a fortune on it (about $1500, or £1140).