I went outside earlier to have a look suitable position of the amp. I really want to keep it stealth look so will not mount it on the back seat or under boot lid unless I have to.
From what I can see on mine there is one fin edge that will need dremmeling to allow the amp to sit further down (I will try to take a pic when it stops raining) and hopefully that will allow the carpet to sit flush.
what I have noticed when looking at pictures is that not all boot pans are the same decision. I think on the E90 it is more shallow and on mine less shallow. But will keep you updated. I was hoping to take out the boot pan, file/dremmel it away and then dynamat but it looks like a pain to remove and not as easy as I thought.
its just frustrating that I have a couple of days off and the weather is crap