How Many Books Do You Have in Your Bag?

So we're going away for a few days over the long weekend.
Back to Virginia for a promotion ceremony, to visit friends, and to shop.
It's a 7-9 hour trip depending upon your speed and traffic, and I'll have to drive halfway there and back.
We'll only be away for a few days, but it begs this question: How many books should I bring with me?
I'm 80 pages from the end of The Long Goodbye (super fantastic book - there's my 5-star review), and know I'll finish that on the way down.
Should I bring just one extra book, or two?
Or maybe 275?
That's about how many are on my Kindle.
Yeah, I'm thinking 275 books, let's go with that.
That should see me through a four day trip.