Sam,
One other thing you need to make sure they give you when the hand the keys over is a letter certifying it is his Jr's Appreci88te foundation car and don't be weird about it or anything, just let them know you would like to have the letter so you can keep it with the car in case you put it in a show or something of that nature, but that little letter can make a big difference if you do decide to sell it in the future. With 7 $25 ticket purchases, you have received a great collectable and it is an unique collectable as you will be able to enjoy it as well as own it, something in the collectors market that is not the norm. JR is one of that group that has won races, although unfortunately never a Champion ship, but is still a well liked driver and at the forefront when people think of Nascar.
Go have fun with it and make sure to take care of it and it will be a moment in your life you will never duplicate. I remember when I just had lunch with his Dad and to this day that is a very special moment in my life. All I got was a sign Dale Letterman Jacket! But I did get to spend about an hour with one of the greats in this sport.