I have an 03 Discovery II. I have an original replacement radio which gets few decibels after install. I have checked under the driver and passenger seat and do not see an amp. Nothing is under the passenger seat as that is where the disc change was which I didn't buy. The driver seat has a what I think is the ECM protected by a metal box but that's it. I checked on the right side of the glove box and there is a Bosch unit but that does not look like the amps pictured on line. Where else could the amp be located to see if a fuse is the cause of low decibels in a newly installed original LR radio?