Hey, shame me if that's what it takes

. I'm just looking for options since the 134a hasn't been doing that good of a job - in my opinion.
I realize the AC in these cars aren't the best in the world. It won't freeze you out like most American vehicles will. But it would be nice to have a system that would cool things down in something less that 8-10 miles of driving in 85*+ weather.
I am relatively sure there is a leak in the system somewhere. Unfortunately I am not handy & have to rely on my local mechanic, who learned his trade at an MB dealership. He has been very informative & is reasonably priced, which has been a life saver since I'm lost once I get past changing the oil (which I do).
So, OK, lay it on me.......tell me what I need to hear.