Yes you will be able to use OEM grill cover, the oem speaker itself sits about an inch out from the door with its own molded spacer.

 

Not sure about the Bose. I have the base head unit. Go to JL Audio's web site and you can download the pdf of the user manual. Also, buy it from an authorized dealer that will accept returns. The Cleansweep has a bypass switch so you can hear the difference with and without signal correction. If you don't think it's worth it you can get your 300 back. I had Tweeter install mine and they have a 30 day return policy. The installer at this store is awesome.

For most JL products, you also get an extended factory warranty if you have an authorized dealer install their products. If you blow it up, go get a new one!! Gotta love it.

I have all JL (cleansweep, comps, sub, 2 amps, wiring) running with the factory base head unit and it has excellent sound quality.

 

Use your crossovers. I am running one JL 500/1 for the sub and one JL 300/4 for the front comps and rear fills. The amps let you control all signals.

 

Do you mind listing your components you bought? Can you keep the Bose HU and install new speakers and amps and sub? I am interested in keeping my Bose HU and upgrading the rest.

 

I replaced my door speakers with Eclipse (front and back) and I put a Memphis sub in the OEM sub location. I added a Rockford amp just for the sub but that wasn't really neccessary. Anyway, just replacing the door speakers make an incredible difference in the sound quality. Well worth the effort.

 

So how do you have the cleansweep wired? seems like you would have the fronts and rears going into the cleansweep and then out to the 300/4. But with the sub, are you bypassing the cleansweep?

 

I upgraded to JL Audio XR650 series. Yes, you can keep your head unit and add subs, amps, speakers.