Ask Brett. You can do it, but my recollection is that the risk is that the high water pressure shooting up under the car could cause a bubble to form at the edge of the film. I was always skittish about car washes before the wrap. And I discovered that my hand washing resulted in a much cleaner car. So, it was worth it to me. Also, Brett will do it for you (guessing he still offers this) as he has availability, at a price that was more than car wash but reasonable to me. It’s been awhile since I had him do it.
I will just say this again. Looking at increasing number of rock chips on hood from 3 months on, with first car, made me unhappy. No rock chips after 14 months in on second car, and preventing damage as noted in earlier post, is very satisfying. There is no question, if I opt to buy-out my lease (yes I wrapped a leased car), or purchase my next one, I will wrap it. I may just get a basic color and do a full wrap in the color I want.