can anyone tell me how to wire 12" interior neons from under the dash to the battery

you run a +power lead to a switch then from the switch to the battery then you run a -chassis ground. the hardest part of it is mouting the switch and the neon. and if you want to run mutiple neons then you need a mutiple pole switch

Go to streetglow.com... They have a good 4 switch panel that you count mount to the roof or on your dash. Since its a 4 switch you can just put 2 neons on the roof and under dash, or in vents and under dash, whatever you want.