Sub mounting depth
 

I was wondering if anyone knew what the mounting depth for the factory sub is?

Depends on the sub,

https://i.ytimg.com/vi/lyxPKIkUSuo/maxresdefault.jpg

But seriously I've never had mine apart

Another curious question: LS models with the sub knock-out - is it simply pre-wired for plug & play or do you have to run wire to radio from scratch?

You would have to look. I doubt the wiring is there, but it might be.

if you want it to look factory, then you can only use a shallow sub.

Or you can put a box back there or build a custom box and fit it in the wheel well..which i was thinking of doing a while back.

regarding the wiring, mine didnt have any wiring back there

I'm planning on doing this and making a tutorial, but I can't even get the time lately to wash her, much less install anything.

My LS has the Pioneer system with the sub, you must be thinking cars that didn't have the Pioneer system option

I cannot remember the exact dimensions but I found and old post of mine where I mentioned it being less than 4" deep.

my hhr also came with the feature i blew my sub currently looking to get another sub would perfer to keep it factory and not mess with any wiring any information on this would help please

As I mentioned in the other thread, a parts yard or try Crutchfield