It is important to consider the tax implications when participating in car sweepstakes, especially if you are a US resident.
The value of the prize is considered as taxable income and must be reported on your tax returns. But don't let this discourage you from
entering these contests. There are ways to manage the tax burden, such as taking out a loan on your new car or selling your old car. 
Overall, winning a car through a sweepstakes can still be a great opportunity, despite the tax implications.