I just bought a VE SS.
I have a twin amp setup. I run a 4x100w unit (very long amp) powering the door speakers and a class-d in a bridge bout 550w/rms running a dual sony explode 12" sub setup. No issues. I actually made some wooden mounts which I bolted to the back of the seat area to bolt the amps to so I can pull the sub box out easier if I need the space without having to upset the setup.
Piss easy, but a long job to do. I dynomatted the boot, the doors. I run 6.5" american sized Venom 3 ways which are more like 7" Australian, so I had to epically gut the holders and stuff. I run some cheapy LOC's from ebay which cost me about $20 each. You do get a bit of interference but it's the price you pay to keep the stock headunit. Just took a bit of work to get it pretty much right.
I electrical taped various wiring, dynomatted around the loc's etc. Trial and error but I only ever have run twin amps.... because otherwise you find the door speakers just arnt loud enough to match the subs travelling down the highway with the windows down.
As long as u get the earths right, cooling of the amps etc. You'll find no issues running twin amps. The vibration I found mostly comes up on the rear parcel shelf, rear number plate and front passengers A frame towards the front.
Cant get it perfect but u can get it close.
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2009 VE SS SILVER SEDAN - Twin Amps... Tune in progress (more for response and power) then outright KW on a dyno
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