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@SyneKK Go into edit mode in OpenIV, drag and drop the Carvariations.meta file to your desktop, open it with notepad and scroll down to the bottom, there should be a line near the bottom that says the following: <sirenSettings value="12345678"/>

(12345678 is just a random number that I put there but it should be different for you)

Regardless, there should be a rather long number after the = symbol, just change that number to the number "1", then save it and replace the original Carvariations.meta file that's in the poltaxi folder in OpenIV with the one you just edited and your lights should now work fine :)