Thanks for your reply boothboy. Between you and Tim with the amount of experience you have dealing with production line "upgrades" i most certainly will have to fix this problem. Getting someone else to drive the car is a problem as they are too scared to drive a left hand drive car.
which leaves me.
I will try some blu tak and pack out the window weather strip . I am trying to see any differences between the LHS and RHS window seals/fit but to look at they are identical. Two vent windows , one whistle. May have to tie some heater hose to my left ear and go for a drive.