I think my ML amp went out and the dealership is asking $1300 to replace it. So i rather put an aftermarket one back there does any1 know how to replace the factory amp? Any diagrams pictures would be appreciated also make and model of the wiring harness would be great! Thanks in advance

 

You can also check Ebay as several have been sold for $100 or so. Not sure if there any any current listings.

 

I checked ebay and it's expensive around $450 + shipping so i don't want to go that route since this is going to be my second replacement. I think they go out pretty easy and i don't know why.

 

Some of the early models did experienced premature failure.
I have seen them sell for cheap on Ebay from time to time. There is a Lexus seller on Ebay that simply over prices everything. He even purchases items on Ebay and then jacks the price 200-400%. Not sure if he is selling the one you saw but you could setup a Ebay automatic search which will notify you. also if you see someone on there selling parts from a Sc430 odds are decent they may be parting out a car. Worth sending them a message.