I have a stock head unit in my 08 LS but I do have the second small antenna for sirus or whatever it is called.

I have done a whole audio system swap in my last car. (2000 eclipse) upgraded alt, two amps, 4 speakers, 1 sub, all new wiring.

My number one thing is will an aftermarket head unit with HDD plug right into the harness and be ready to go for GPS and SIRUS?

Also, has anyone put the material inside their HHR to block road noise?

 

Lots of them have deadened the whole car, and there is adaptors to connect the controls and aftermarket head units. One that comes to mind is American & Proud, he did all that stuff. I didn't do the deadening yet, but did the head and speakers, sounds 10 times better than the pioneer system, even without changing the amp and , sub.

 

Thanks.