I didn't want to take the chance of having someone with limited knowledge working on my new car. They have to drill holes in the trunk lid and if they're not positioned right it wouldn't look good. Also, I watched the Lexus mechanic do the job and he knew exactly what wires to attach the LED light from the spoiler, how to remove the inside paneling and in general he was experienced in doing this job efficiently. Actually, my Lexus dealer wanted $90 per hour and putting on a spoiler is considered a 2 hour job. I talked him down and he did the job for $120 plus tax.
This is a fairly simple job to do though if the person doing it is careful. Remember though the old adage, "Don't be Penny Wise and Pound Foolish".