In addition to eating in the car, I never set foot in any shop... ever. The only thing I was ever tempted to buy was an overpriced T-shirt that had Son of Beast on it because it is the tallest/fastest and may not be around for much longer.
I hate concept of hiring employees to bother guests and try to take their picture. Why spend $20 on a picture you could have taken with your phone? Ohh, and a SOB ride photo was tempting but again so grossly overpriced I couldn't bring myself to get it.
Still, I love the KI attractions and THAT'S what I come for. Once I'm in, I hold onto my $$$$