Heres a fix for those of you who may be experiencing difficulties with your clubman heater tap.

Bits youll need are:
1 x Jayair universal heater tap 5/8" HA4008
2 x Heater hose Holden VP 3.8 litre V6 CH1779

I purchased these bits from Bursons.
You may be able to do it without the heater hoses but youll need to find a way to match the 1/2" outlet from the heater to the tap which is 5/8". I found that the Holden heater hose had a nice 5/8 to nearly 1/2" reduction at one end complete with a right angle bend which enables to hose to point up towards where the heater hose goes out through the firewall box section. (Check when you buy the hoses that one end actually does reduce to about 1/2. I may have just got a couple that were not manufactured correctly)

You will need to modify the original tap mounting bracket by cutting off the two arms and then bending the bracket flat so the the new tap aligns with the heater inlet pipe, fairly easy to do. I then cable tied the tap to the modified bracket for some support.

The cable operates the same as a normal clubman. I had to form a circle on the end on the cable inner to fit on the tap operating post and shorten the outer cable slightly to get the operating range. (I think my cable had been straightened not sure what the original set up looked like)

Ive added some photos that may help with my somewhat inexpert description.