Anyone know where I can get this installed?

Technically lights like that would be illegal. Instead get some retroreflector tape

Is it illegal? Absolutely.
Do the cops do anything about it? Absolutely not.
Meanwhile I'm getting blinded by lifted trucks with overhead lights and a LED light bars on the grills
- I drive a small car, I absolutely hate it when pavement princesses come up from behind and blind me. In general I want to give the cops as little reason to issue tickets as possible. Retroreflectors are why we can see signs from a distance when it's pitch black, so it's a good option that doesn't technically break any laws even if the law is basically completely unenforced
- Yeah cops don't even pull people over with unaimed blue HIDs in halogen housings even though they can be spotted from miles away. The dispatcher also just wouldn't believe you if you reported someone for having a James Bond gadget on their car.
I know a few people with aftermarket reverse lights. Not all of them have a hidden override switch which turns them on when they aren’t in reverse…
That wouldn't focus the beam back in the manner intended. Mirror pointed in the right direction would

Honestly I just want a display in the back that has a few preset messages set to a button in the front. Stuff like "Please give me more space" or "Your headlights are too bright".

Barring that, would love a mirror that redirects headlights back to the driver's face. If I can deal with it, you can deal with it too.

- Nothing new under the sun, I guess! And here I thought I was clever and original.
I want one of those, too. Ironically, I think I'd be using the "it's dark; turn on your headlights" preset more often than the “your headlights are too bright” one. (I blame daytime running lights: drivers see the ground lit up in front of them and don't realize they still have to turn the headlight switch in order for their taillights to come on too.)
- I blame dashboards that are backlit when the headlights are off. On my 07 corolla I KNOW I when I forget my lights, because my dash is a black void.
"POLICE follow me"

A Mercedes-Benz chassis code W202 (90s C class, other E and S likely work too) can do this with minimal modification, only needing the lights to activate when near vertical (or just reflectors, no mod required). The car has no check for if the car is in motion or at what speed when the trunk is popped open via the center console. This also lifts up the license plate, obscuring it from view. You can travel about 45mph (72kph) before the wind resistance starts to push the trunk down. The springs are strong so unknown how fast you'd need to go before it was ineffective for this purpose/target car, or to attempt an 'auto close'.

Do what you will with this information.

Some truckers have this. Years ago I hit a deer with my Buick regal. The only thing wrong was the front right headlight was pointed upward. Picture the laziest eye you've ever seen... Before I got it fixed I must have pointed the thing right at a trucker's mirror and he turned his 1500 jigawatt spotlight on me and moved into the center to block me from passing. I was leading ~10 cars up the passing lane at the time. I'm sorry for blinding you dude, but now everyone on the road is blind with no way to resolve it. I can't get my headlight out of his mirror until I overtake. I guess he assumed I had my high beams on and was waiting for me to turn them off. Real 4d chess move...

with no way to resolve it.
I mean, you could've jury-rigged the light to point in roughly the correct direction, disconnected it, or even just not driven at night until it could be repaired. You didn't have to create that dangerous situation.
- Btw it's "jerry rigged", unless truck driver and OP are in court for the altercation!
Thats why I stopped using the fog light to fuck up high beamers. It’s just another fight you‘re waiting to get in. People will overtake and brakecheck you or do the same just to get back at you. A large portion of the polulation is literally braindead. I just step off the gas now and make them overtake since they think I‘m too dumb to find the gas pedal. Less hustle, faster solution.
- A large portion of the polulation is literally braindead.
  Yup. Just joining a dating app revealed just how many trump supporters and Covid deniers are out there. Tonnes. And not even in America. Fucking scary.
  Side note: If you find smart people, do not let them go. FOMO will just get you alone and deny good shit from happening.
- I like to give people a thumbs-down👎when they do something dumb while driving; add a little frown and a slow head shake of disappointment

Can I get a Trunk Monkey instead?

So are you responsible for the criminal acts of your trunk money?
- One of the skits showed the trunk monkey, not the human, going to jail for bribery. So I would say no.

What? 8 year old memes?!

We brangin all dat shit back son
Straight from the vault!
The classics...
And our laws have done nothing to stop them from blinding us from behind, from the side mirrors and from incoming traffic. 8 years!
Need a new version of the meme that's a bit stronger, maybe.
- This problem has been completely solved by auto-dimming mirrors.
Memes never die, they just become "vintage"...

This would be a really easy mod if you're feeling brave.

Rear fog light does its job in that case. There's no need for the upgrade shown above.

Unless you're American and thus don't get to have rear fog lights.
- You do if you buy a German car. Even US spec ones have rear fogs.
But on most cars the rear fog light is one (sometimes two) 21 watts incandescent bulb behind red plastic. Same as a single brake light. That's not going to bother someone with blinding LED headlights.

Truly I was in the slow lane with nobody else on the road with 3 lanes, and this douche in a CRV felt the need to shine brights.

Wind would close the trunk

You're assuming all the button does is pop the latch. Make it a self-opening trunk with pistons and it'd work fine.
Not if it's opened with a hydraulic piston. 😌

bus lane enforcement camera

Both cars are in the middle lane. The left lane is the passing lane. Do you know how to make a proper pass?
- Every lane except the rightmost is the passing lane. You only need to be in the third lane over if you're overtaking a car that is itself also overtaking a car.
The middle lane is the safest lane to stay in so long as you’re doing the speed limit. This is even taught in modern driving courses.
- It is also illegal to be in, at least in the UK where your instance probably is. Fixed penalty illegal, not prison time.