Not really. When your car will start rusting inside, because water got in through rusted through holes, then without extensive repair it can't be saved. Such repair will be more expensive than remaining value of the car.
Wiring is even more problematic. When PVC will degrade, you need to change whole wiring not just the broken part, because changing only the broken part will make more problems in different parts thanks to the fact that you will need to manipulate with rest of the harness and degraded PVC has tendency to get hard and break off. Wiring for the car can cost several thousand EUR because it is basically manual labor without much prospect for automation. If it is car older than 10 years, it makes no sense to do that.