I use ACF on all my cars, even new. Sprayed through a paint gun and using a compressor. Great stuff, used in aviation so difficult to think it might have an adverse affect on some materials.
My company (before I retired) was the UK importer for ACF-50, I queried with the manufacturer the possible effect of it on the running board rubbers before I used it on my MOG or recommended it to other Morgan owners. They assured me that it was perfectly safe, it could possibly have an effect on 100% pure rubber but it's almost impossible to find that on any cars, motorbikes or aircraft now. I've been using it for 12 years so far with no apparent problems. The only caution I would offer is not to spray it on rubber drive belts as it could cause slippage (mostly for motorbikes) or brake surfaces.
