You payed for the excellent 77MP and you wanna fit Sony speakers
Noooooooooooo..... get a set of Focal components, or even Infinity. If you get any Sony, Kenwood, Pioneer etc crap, your head unit is completely wasted. You just bought a GTA and you want to fit 185/65/15 steel wheels on it, with the suspension of the 147 1.6 105bhp and you expect from it to work well.. You shouldnt get that head unit at first place.
Sorry if I sound like i have bad manners, no offence, but I ve been messing with ICE for ages and all the time its the same story: its too sad to see ppl spending all their money on fancy and expensive head units and spend the less money they can on the speakers. Remember what I ll say now: If you ever meet a 156 with the cheapest Pioneer hu but with a set of properly fitted Focal speakers, it will completely beat your MP77 + Sony speakers combination. You got a great head unit, and you re gonna condemn it to work with crap speakers and no amplifier, because you re afraid of trim removal.
I ve fitted ICE systems at many cars, and I ll only tell you one thing: Whatever creaks or any problems you ll get, it will be from the crap build quality or reliability of the car, not from the installing procedure, and you re gonna get them anyway. I ve dismanlted my own car many times, and i dont have a single creak (touch wood) so far. I had many creaks when I bought the car, and I had to visit the dealer more than once to fix them. That was before fitting the ice.
So if you have the money, go for it. And enjoy it. Get some decent speakers for a start, and if you re willing to go further, fit an amplifier and a Dynamat door sound proofing kit
. This will make your door solid, without messing up with the door's functions at any way, and will make the speaker work like its fitted in a closed box, giving you crisp, accurate and deep bass. Especially the Focals, can go so low on a sealed door that you ll feel like you have a small subwoofer fitted. Not to mention that any door trim creaks will vanish, will the road noise will decrease.
I m sure after all these, you ll still going to get a cheap set of Sonys, but at least i ve done my duty