JBL System tweeter upgrade - Better than Subaru tweeters

Has anyone tried the 3" coaxial by cdt yet? Maybe easier to fit what is the over all measurement of the 3.5 od. ? I think their 3" is 93 pr 94mm I'm in the process of trying the 2 inch coaxial it's supposed to play down to 250hz but is recommended to have high pass of 500 for power handling though I've read people using it at 250hz with no problems. They have a dvc mid,,/,tweet I'm wanting to try above my rear view mirror you can connect both channels to 1 for a center..that's the only way I'll get my ohm load down to 2 with their 2" coaxial in my dash. Might be an option for some that are using 4ohm speakers in dash or other places running jbl on them. Just some info I came across that single dvc is 99 $