The dashboard hoop requires fitment of a specific trim, which is sort of in the middle between the IVA trim used on the lights and that fitted to the air filter housing inlet. Similarly to the filter housing trim the dash trim contains an internal metal structure which can be difficult to cut.
Before starting the process of fitting the trim I came to the conclusion it was probably going to be a tight fit, everything else had been so there was no reason to suspect this would be any different. I therefore went off to the Internet to review other build blogs. My research confirmed my suspicion, it was tight and difficult to fit. Others had used hot water to soften the trim but concluded such an approach didn't help, I therefore opted for something else. Logically heating or warming the trim was still the preferred strategy, it would both soften the stiff rubber and hopefully expanding the metal to permit it to pass over the edge of the dash hoop with greater ease. I opted to seat the entire trim across the top of a hot radiator, and it certainly worked. The trim absorbed the heat energy and became very pliable, so off I went with to the garage.
Fitting the trim over the hoop was really easy, the initial section clipped over with moderate force, and sat neatly into place. It was then just a simple case of working my way around the hoop. It was at this point in my rush to fit I thought I've not measured or cut the other end. I therefore stopped, neatly cut the drivers side and went to check the IVA notes.
At this point I made a discovery. There is no mention of how much over hang is required from the bottom of the hoop, however there is need to use the remaining off cut on the leading edge of the catalytic converter heat shield. It is going to be important to get a clean cut on the passenger side with minimal wastage!
I went back to the car to continue. I used about 8.5mm over hang from the end of the hoop on the drivers side and worked my way around the hoop to the passenger side. I then placed detailing low tack masking tape to mark a similar over hang. The trim was then removed to around the centre of the dash and safely cut on the passenger side. One cut it was refitted, it is worth noting I rounded off the leading edge of the cuts too.
At this point the hoop trim process was complete.
Since I had the cutters out and the trim to hand I went on to fit the trim to the leading edge of the heat shield which I'd already fitted around the catalytic converter. If you are reading this blog prior to attempting the heat shield I would recommend fitting the hoop trim first and then fitting the remainder to the heat shield, it's just easier that way and there is no impact to anything else.
Conclusion use a hot radiator for around 1 hour before fitting the the trim. The trim is totally happy with contact with the hot radiator and becomes really easy to fit, although it was about 10'c in my garage so it cools and stiffens pretty quick, you need to work fast.