Greetings to fellow GLA owners and enthusiasts. I purchased a 2017 GLA250 4Matic for my wife because she wanted it. I acknowledge that the Harman Kardon sound system is sometimes 'panned' by other audiophiles - but I feel it would be an improvement over the stock system that came with her GLA. That having been said, I acquired a removed system (really, just the speakers and mounts) from a salvage yard via eBay. Everything arrived and I have discovered a couple of things rather quickly: (1) swapping the front tweeters is very easy. (2) swapping the door speakers required special rivets which I happen to have ordered. (3) I think the rear doors must have had a tweeter mounted somewhere in the door handle area? I haven't located that yet. (4) there is apparently some speaker to install in the dash. (5) the factory HK sub has the mounts in place in the trunk --- the wiring harness is another story and *THAT* is what I am hoping someone might be able to help with.

I made a poor assumption that there was just (1) style of wiring loom and that on removal on the trunk lining and I would find the factory connectors stowed there. I did not. I found what appears to be an electronics box on the left hand side of the trunk where what is very likely fiber optic cables for the rear camera ... does anyone know if they happened to stow that connection on the RIGHT hand side on the trunk?

Also -- it would appear that a separate "Logic 7" amplifier must have been installed in the subwoofer assy; it is clearly missing and I wonder if that is merely to drive the speakers from the factory HK system.

Anyway ... I acknowledge that there are very likely better sound systems out there - I just want to get her GLA to the HK system because it will be far better than the entry level system.

Any help is greatly appreciated.....