That has been going on for a long time. Happened to me in 1974 near Flagstaff, AZ. A 68 Beetle with New York plates pulled in for gas while it was being filled he looked under the back of the car and told me my shocks were leaking. and that he had the parts and could fix it immediately. I said no right away simply because I didn't have the money to fix the car.Years or decades ago there was a place in the news (I am thinking on Merritt Pkwy in CT) where they had an oil squirter with oil and metal filings and would squirt it on the vehicle's shocks and then point out to the driver that the shocks were leaking and needed to be replaced. Until they did it a second time to someone who said "you replaced my shocks last month, what is going on?"
not because I thought it was a scam.