There is a way
OK here goes. I got fed up with all these 'renault experts' scare mongering and telling tales of illegal and legal top ups but heres my story.
As I said I was fed up with the renault bull¤¤¤¤ so investigated the old fashioned way, with a decent toolshop a pencil, and pad to find that renault in their typically french way decided to remove the high side port on the laguna and only have the low side - with a twist. it is fitted with a high side port valve. this appears to be welded to the dehydration cannister just to make sure you cant replace it with a retrofit kit or attach a standard low side port such as is found on any top up kit .
The bottom line is that any air con engineer with half a brain would just reverse their hoses and use the high side hose on the low side fill system. So yesterday i purchased a couple of cans of r134a with leak stop and oil, a high side service port valve, a standard hose with 1/4 couplers and can adapter with guage and topped up the system with no problems at all That was a week ago and ~I have had ice cold air con since.
Whilst the set up cost the same as a renault top up, i now have the tools to top up whenever i want and dont have to be ripped off and only now need to buy refrigerant which is readily available for 15.00.
Oh and by the way, it does not require you to be licenced to do this only to remove the old r12 systems which these are not.