choosing right harness
 

Ok i want to put in a aftermarket radio i have onstar but I dont use it, i know theres two harnesses that will work the gmlan03\without onstar and the gmlan04 with onstar,... if i where to put the gmlan03 on would that affect me or my car cause i have onstar on it? thanks

I have an 08 with Onstar and I used the Gmslan3 from Crutchfield. It is made for Onstar! I'm able to use Onstar and chimes.

You don't mention what year, model or stero type your HHR has. These all make a difference as to what to use.

Go to www.Crutcfield.com and put your info in. The answer will be there.

can i install with just a regular harness i don't mind lossing the chimes or onstar

Sure you can. I wish I would have done the same thing sometimes. That is till I almost left my keys in the car while out of town and was reminded by the chime. That in itself made it worth buying the lan3.