So I decided to try the Bitsashitty Eclipse Fast n Furious style vent mod
Difference was I tried to keep some of the extra flap at the back of the vent.

To the left of the glove box I had to shave part back so it would fit inside the pipe work.

In the middle tried the option to sand back the vent so it was the same size as the original vent, it fit in well but it sat so deep I couldn't utilise the same groove and the mazda vent holders.
So I kept this one larger so the grove was at the right distance.

Because the factory pipe is a weird shape I only kept half of the blocker deeper in the vent.
