If it's any consolation, I was there earlier today to pick up something for my S and all the Model 3's (loads of them) were inside, under cover, and out of the way of the general population. I don't think your car will be getting dirty and scratched up.
I know it sucks waiting, but remember you've essentially bought a car from a tech startup, not a 100 year old car company. The guys at Tesla are getting absolutely smashed getting these Model 3's out at the moment. The staff are doing their best with very few days off, and a massive workload, so whatever happens - try and be kind to them!
All will be forgotten when you get behind the wheel of your amazing new car.