Some kids grow up in a town. You grew up in a rig, small and wiry, handed a wrench before you could reach the pedals, sent into the crawlspaces no grown hauler could fit through. A two-kilometre nuclear land-train was your street, your school and your home, and you know every bolt of one by touch.
Choose one of the following skill boons.
A personal multi-tool, edges rounded from use, that somehow fits every fastener on every rig you have ever met. You would sooner lose a finger than lose it.
You have advantage when locating a fault in a vehicle, or when squeezing through its access spaces, ducts and crawlways.
You sleep better to the hum of a running engine, and badly without it.
You distrust anything that does not rattle a little. Machines that are too quiet are hiding something.