I learned this trick from another website and cost is $0. I got tired of my antenna banging and dragging the garage door as I pulled in (made significantly worse with bigger tires and level kit) so I just remove the factory antennae. Measured down 6-7" and cut off. Removed the ball at the top of the antennae with a vise and elbow grease. Reinstalled the ball on top of now shorter antennae by carefully bouncing off concrete slab a few times. Quick light coat of black spray paint for any accidental scuffs I made and BAM a new antennae that does bang or drag with the total investment of $0.