Cars rented in Switzerland certainly have the Swiss toll sticker, sometimes they even have the Austrian one. Sixt-USA offers good rates. I would mention it in the booking. If you take the car for longer, avoid renting at the airport (substantial surcharge). Sixt delivers eg to the Hilton or the Sheraton in ZRH free of charge. If you travel around these countries, buy your gas in Austria and Switzerland. Thehave substantially lower taxes and it can easily safe you 20 bucks per filling.