Advice on cutting out more of a-pillar

[cpassmore1]

I did a test fit and test 'listen' of drivers in place (held in with blue masking tape) and they sounded forced and 'hollow' until I brought the low frequency cutoff to 1khz (high @ 5500hz). Driver is 4" Morel carbon nano mw4. Googling (AI) suggested I didn't have enough airspace behind the driver and that's what was causing the poor quality. I had my suspicions as I was building this I didn't have enough of an opening. Wondering if anyone has any knowledge on how damaging it would be to the vent being connected to the a-pillar facade if I was to cut out the green highlighted area. This is a relatively older version as I've cleaned up the fiberglass sanding and bondo but wanted to show shape and proportions. I haven't done any butyl on the inside but didn't feel any vibration in the panel when playing.

Thanks for any input.

 

[UNBROKEN]

When I had a-pillars I took those completely out and capped the vent coming out of the dash. It was like that for 100K miles…never missed them for a second.
You’ll always be chasing some imaging issues with pillars in these cars. The two of us that seriously compete with ST’s have both gone to dash mount…it’s sooo much better.

 

[cpassmore1]

I get it… my mother lives in Beaumont… you don't have to worry about frost on the windows. I'm in Illinois and it gets cold.

I'm not in a position where I want to cut into the dash and not looking to compete… just want good sound. I tested out the dash location with some small plywood baffles and liked it but decided not to go that direction because of how it'd have to connect to the a-pillar (at the base) to open up the airspace needed for the driver (not cutting into dash).

Are the only things connecting the vent to the facade the melt points? If I were to cut those away I'd have to fashion a new clamp… holes and resin/bond? Does the plastic used for these pieces melt to itself with MEK?