whell there those racecar hold down tabs , you can put a little petlock on those too
that would look a little better than a chain through the hood , the truck might not be verry desireable to thiefs to start with and making it harder to steal might discourrage them to try , on the other hand it might work as a red flag that either lets them try harder or set it on fire
another option might be to run a chain over the rearaxle to a stormdrain basicly chaining the truck to the road , allthough early mornings tend to make one less sharp untill iether the rearaxle flies from under the car or you notice a clanging noise under the truck farther down the road