If your dog has been peeing in your car seat, there are a few things you can do to clean it up. You can try using a plunger to suction onto the offending object and pull until the liquid is forced out. You can also use a vacuum cleaner with the hose attachment to suck the liquid up into the machine. Finally, you could place a cloth over the top of the car seat and wait for it to dry before putting your dog back in his spot.