Ceramic films do an outstanding job of reducing interior heat versus the traditional metallic-based films. I've read where metallic-based films can potentially interfere with radio and radar, depending upon how much metal is actually contained in the film. I went with the Hüper Optik brand ceramic tint when I had my A5 and could definitely tell there was a significant reduction in heat when the car had been left outside in the sun for an extended period. The tint also blocks 99% of UV rays, which is great long-term for preserving your interior's color.
I think $475 is a bit on the high side. I only paid $379 from a high-quality, professional window tinter.
I know there have been several folks on here who went with ceramic tint. One user posted how delicate the Hüper Optik brand is, but I never saw any scratches on mine. (
details here)