When first (re)built the transmission tunnel was a shameful cobble of whatever offcuts of metal were laying around. Due to the engine & gearbox being further back than standard (sportscar weight distribution doncha know?) a standard one wasn't going to fit either so Miketomcat spun his sticky web of glass and resin and made me a perfectly snug fitting one with a little cubby for good measure:
This cut down noise, heat, draughts, and squirrel ingress by a huge amount and made things much more civilised. It also unbolts & lifts out pretty easily in two sections for access.
Mike would later make us a new R380 transmission tunnel for the ambulance too: