The W202 95 - 00 C class gets a fuel filling issue due to a vent valve, not sure if this is same as W210 or not.

Fixing this car would be a non issue as the problem is limited to the filler / tank / vapor canister.

I once fixed a customers 90's GM car that suddenly stopped taking fuel. Someone pealed off the gas pump weights and measures cert sticker, folded it up and stuck it into the gas nozzle. The sticker went down the fill tube, expanded then blocked the roll over check valve.