Jobsi, what was your build date? I just installed '19 gt350 mirrors on my '18 LFG GT350 just like yours and mine don't work....? I left the blis/defrost glass in, you think that has something to do with it? Any help is appreciated, really bummed as I thought these would be plug n play on my '18So I can 100% confirm that a 2019 GT350 mirror is plug and play to a 2018 GT350 . I got a really great deal on a pair of 19 mirrors off a wrecked gt350r the options on the mirror where blind spot , defrost and puddle lamps. I removed my 18 mirrors and also removed my caps and glass the 19 mirror needed caps. I than removed the 19 glass and unhooked the blind spot and defrost. Installed my glass and cap and put everything back together and it all works perfect.