Well took the plunge today, all straight forward. Not sure how long you're supposed leave the can on? Can anyone advise?. We had it on for 10 mins. Managed to get his vent temp down to about 12c, still too high. I reckon still got half a can. I think he may have some other problems, sticker near 134a sign saying that a dye test had been done in 2003. pollen filter looked dirty too. The dealer threw in a 12 month warranty with the car when he got it last Feb. I said he should check if AC is included before we try adding anymore gas