ptpixel

A company called Acexxon have made honeycomb inserts for the rear bumper reflectors for the A3 / A5 (see image below) as well as some VW golf variants. I messaged them the other day asking about A4 inserts and I got the following response:

On Aliexpress these inserts seem to be priced anywhere from $25USD to $120USD. If there was any interest I could enquire about a group buy discount for when these become available. Let me know and I'll find out, might also post to other A4/S4 forums too.

SpeedyTheSnail

I live in an area that I want my car as visible as possible, because the drivers are really that dumb. This is definitely a niche item but not something I'd ever purchase, if anything, I'd opt to get some glow in the dark reflectors that stay bright for a few hours after darkness, with a reflective coating as well.

Edit: I should clarify that I've had 3 cars totaled over the past 5 years, all from people on their stupid cell phones. Also had a hit and run, which only dented my car. If you could get some of these that drop caltrops if somebody gets too close, that would be awesome! Just kidding, I know that's not legal, but It'd be nice to have some useful countermeasures .