Some guys are smart - they make a talking point of a necessity and get not only business, but free publicity in the bargain... I think that is the way to go... Requires a bit of shameless self promotion, but I think you would be able to manage, considering it is good for them too...
There should be this air around... "cars from this guy just need a whiff of gas to go..." "I dunno what he does to his vehicles, but I would rather drive a wreck from him than a new vehicle - It saves me half my monthly payment on the car..." "If it is from Christ's I would get by with half what I now pay for gas..."
Then you could openly say what you do to the vehicles, and guys would not just believe but flock to you, for the mods, and maybe would be ready to pay a premium (however small) for it too...
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