If your paying a premium for an option, regardless of how much you use it, it better be in that car and it better be functional. Yes I would not personally want to leave my vehicle at the hands of the stealership as their many documented cases of people leaving their car and the personnel taking a joyride.... But Yes I can sympathize with the OP, you pay for an option, it better be there LOL. If you wanna lemon law the vehicle (which is an extreme measure as its only a tailgate and not systemic failure of the CAN-bus) you can. As long as your dealer records for your particular vehicle have the necessary time stamps for the possession of the vehicle (7+ weeks).
BMW and Mercedes Build Beta Products!
Lexus build Release Candidate Products!
Why does this matter?
CAUSE EVERY TIME someone says Lexus has better build quality, one should consider what Toyota their Lexus Engine and chassis platform comes out of and how long that part has been tested in the real world!