Do you buy tweeters and swap out tweeters regularly? Do you want a way to be able to easily mount tweeters on-axis and make them look nice? Do you want to mount tweeters up on your A-pillars to avoid as many diffracting surfaces as possible?
If you answered yes to any one of these questions, I have just the solution for you!! My friend Glenn (GLN305), has come up with a very inexpensive solution for tweeter mounting that allows for easy swapping out of tweeters, makes it easy to mount tweeters on-axis, provides a certain degree of adjustability, and makes the mounting look nice. Glenn was kind enough to install a pair of Scanspeak Illuminator 2004-6020 tweeters in the A-pillars of my Mazdaspeed 3 and so I took pictures so that I could share his very innovative design with others on the forum.
Parts: (1) 2 x PVC end caps (find ones that fit your tweeters, the ones in the picture are 1.5" diameter; some tweeters may need bigger end caps), (2) threaded pipes (in Home Depot these are called steel nipples. Yes, the jokes about nuts and nipples are endless) these are threaded and used in lamps to thread the Power cord through), (3) hex nuts, a (4) a can of bed liner to create texture, and (5) optionally, a can of spray paint in a color that matches your car.