Unnamed for a reason

Okay so, not only that these were the issues, but there was also a supplemental </sirens> that was making it do some crazy stuff. Everything works fine now! @Aquamenti, @NeulandInternet you guys are the governors! Aitäh! Vielen Dank!

You've made a mistake with the carcols file. First off, it starts with </Sirens> but it should be <Sirens>. There also seems to be a redundant <Item> right after it.

Okay so, not only that these were the issues, but there was also a supplemental </sirens> that was making it do some crazy stuff. Everything works fine now! @Aquamenti, @NeulandInternet you guys are the governors! Aitäh! Vielen Dank!

Umm, no. Sirensettings are defined by carcols, so as long as the sirensetting you refer to in your carvariations (for example: 13) exists in carcols.ymt then it should work fine.
I suggest you carefully read over the readme that comes with Lundy's download and make sure you followed the steps through. You can start by checking your carvariations lines, what is the sirensetting value there.

Have you tried it after adding the audionamehash? That's what gives you a working siren in the first place so without it there would be no siren, no lights, no nothing. 

No worries, you've already done enough. Danke!

No Problem. 
The original police cars don't have their audioNameHash Set in the vehicles.meta. 

Fascinating, it wasn't set in the original file I used, that had to be the issue. Thanks a lot ;)

Did you Set the AudioNameHash in the vehicles.meta? E.g. <AudioNameHash>POLICE3<AudioNameHash/>?