The first time I got a Toyota, I brought it for regular maintenance and they cleaned my car at the end. I was shocked because I never experienced this before, but the technician told me it was free and standard procedure.
At least they understood that if you see clean cars around you when you drive, you're more likely to buy the brand later, and keep happy clients.
Many dealership service centers have gone to great lengths to buck the stereotype they had acquired and have realized how a good experience with the service side of the business helps feed back into the sales side of the business.
I’m also a data point for excellent Toyota service from the dealership where we bought our Prius. From the concierge who holds your hand throughout the visit, to the free lunch voucher in their pleasant little cafeteria (sadly, closed after covid), to the couple of years of free oil changes, I actually looked forward to bringing the car in. And they cleaned it as well, a quick interior vacuum at least.
At least they understood that if you see clean cars around you when you drive, you're more likely to buy the brand later, and keep happy clients.