This was the install on my mk1
(a bit grubby but you get the idea)
I plan to tee the throttle by-pass into the main hose as currently it draws hot air at tick over so the ECU applies the correct map for a hot intake.
As soon as you start to drive it has to adjust to a much cooler intake.
On the mk1 I still had the resonator box in place and the car tended to run about 5' above ambient.
On the mk2 there is no resonator box and it seems to be up to about 8' above.
I plan to cover the gap under the chassis rail with a plastic panel to stop heat from the radiator drifting into the under wing area.