With all this hot weather i now think i have to add air-con to my MY00, does anyone know how much this is and apart from Subaru dealers who else does this in the London/Essex area.

I think Grade A do them for about 400 quid +VAT, then you would have to fit it, and have it re-gassed (about 80-90 quid for re-gassing at the dearest)

I think it is about £1000 from a dealer, supplied and fitted.

I thought it was about 1500 quid fitted, at least thats what they told me a while back

£995 from subaru, bit pricey though. Does it have any effect on performance or fuel consumption??

with it on you will use from 10 - 15% more petrol if memory serves, and as the aircon runs off the engine you will have the slightest power drain when you have this turned on, to be fair i dont notice the power drain, although i can watch the petrol gauge plummet at the best of times :)

I heard somewhere that air con is more economical than driving with the windows down, more drag I guess.

£995 from subaru, bit pricey though. Does it have any effect on performance or fuel consumption??

Most definately.