Like it says, I think I will be upgrading the kick panel speakers in my GSL-SE. I am going to make replacement panels to get a 5 1/4 or even a 6 1/2" woofer in the the original location (don't want to move them to the doors or anything).

So, if I go the component route, where is the optimal place to mount the tweeters? I've heard in the A/C vents (stealthy, but kinda weird), maybe up in the corners of the dash, or maybe down on the kick panel but aiming up at the driver.

It seems like these are all less than ideal, don't you want to keep the two components close to each other in this installation. I'm trying to keep a close to stock look.

Right on.

 

yeah you want to keep them as close to the woofer as possible so the sound blends together as it hits your ears. Wherever you put them make sure they are facing in the direction of your head, tweeters that don't play towards you are useless as their frequencies are super high.

 

The tweets are recommended to be placed within 6" of the woofer for optimal performance.