A lot of the Cup, Nationwide & Trucks use wraps just because they have multipule teams. They just build a bunch of the same vehicles and then wrap them with the proper stuff depending on who the driver is for that race.
There have been a couple of times that one driver from a multi driver team wrecks both the primary and the back-up car. Then they just re-wrap the car for the driver that wrecked his stuff and off he/she is again.
Do you think that the wraps are any lighter than a painted car?