Just had mine fixed. After spending some time looking for the bright yellow dye from the pipes and not being able to see it, we regassed it and listened for the hiss. Hidden behind the air box, drivers headlamp and whatever else lurks on that side of the engine bay are 2 air con pipes. The smaller one had a tiny hole in it, but leaked out in 10 minutes. Never would have seen it! Repaired with an aeroquip hose unit and regassed. I also had track rod end, both drop links on the anti rollbar, pollen filter, water temp sender and tracked for £275. Lovely and cold, even when it was 32C outside!