When I had mine, the first thing I did was remove the overlong bolt to allow operation of Q/R steering wheel. Good security feature. It's true you have to be careful it's fully engaged but pretty obvious when not I found.
I had fitted from new by dealer a full aftermarket screen but don't recall any gaps at bottom of pillar. The top bolt did allow attachment of aftermarket rear view mirror though.
The best mod I did was fitting the then available Stage 1 kit from MMC including pipes that allow retention of heat shields and S & S air filter. Apart from the sound the bottom end was smoothed out considerably with clean pull from 2500 instead of 3000 rpm.
