I've noticed that when I plug the iPad into the car to listen to ie music videos it says not charging is there anyway to change that . ?
You need to make sure you buy a car charger rated at 2.1 amps, for a iPad 2 fast charge to take place. I can recommend the Griffin GC23095.
I don't know if you can change the charing notification. However, lack of notification does not necessarily mean it is not charging. As posted by others, some charger put out less power than others. Sometimes, the iPad will not know it is charging on a low-powered charger. My suggestion is to ignore the lack of charge indication, use your existing charger, and listen to your music. If your iPad runs out of battery power under these conditions, then consider alternative methods.