Can anyone recommend games my 4 year old will enjoy/be able to do? He loves driving the tank on Wii Play (he steers with the nunchuck, I fire - it's hilarious and we get further than I do on my own!). He tried Mario & Sonic Olympics at a friends and enjoyed it. He also had a go on Mario Kart 64, which was a bit tricky for him but a big hit. What's the easiest racing/driving game out there??