I rented with Silvercar in Las Vegas this past weekend. Since I recently purchased a CPO S4, Audi sent me a coupon for 2 free days with 2 paid days.
Upon arriving in Las Vegas, the app didn't allow me to request pickup. Not to worry, though, as they send a text message the morning of your arrival. I texted that I was ready to be picked up and received an immediate response. I met the driver in the Uber area of the rental car center. They brought the car to me; I didn't have to drive back to the facility (which is only about 2 minutes away). I had a 2017 model with 1100 miles. The car was great. Coming from my '16 at home to the '17 made me realize how many improvements the '17 models have.
When you drop the car off, you hit "home" on the navigation and are directed to the facility. Check in was a breeze and the attendant drove me back to the rental car center.
I would definitely rent with Silvercar again. Beats the Altima I would likely have received at National.