I start with a list
-i step on the brakes and the parking lights turn on.
-left turn signal works, but the right doesnt n the bulbs are good.
-when the headlights are on as i drive they either get really dim or really bright they like flash. also i was driving and both headlights blew at the same time once.
-when i step on the gas my tach works sometimes and other times goes whereever it wants.
-whenever i step on the gas my radio quits playing music, when i left off it comes back on.

i have no idea and all that i know is people said check your grounds and i have.

time to bite the bullet: http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=20102

thats what i was leaning towards

Are the correct bulbs installed? I've seen single element bulbs installed when double elements should have been. Also could just be bad ground.

I doubt if new wire will help with a bulb that is not getting a good ground.