vacuum sealed kielbasa in a hot car for 18 hours - is it still good?
Sounds like you're going to need some new kielbasa. 

Kielbasa isn't fermented, and needs to be refrigerated to stay good. Vacuum sealing reduces the oxygen in the package, slowing down oxidation and inhibiting the growth of some types of bacteria when combined with refrigeration, but that kielbasa won't stand a chance in a hot car.