A car is really not a good idea either. The traffic on LV Boulevard is horrendous.
True story: Friends and I were staying at Mandalay Bay...two of them wanted to drive to the Sahara down the street. I and others said we’d walk. We who walked had to wait almost 45 minutes for our friends who drove.
We go to LV every fall for the Professional Bullriding Final (the PBR), we are there for almost 2 weeks. The first year we didn’t rent a car and took Taxis and it was a nightmare of waiting and the Taxis take the most congested route so they can get as much out of you as possible. After that we always have our own car and by using a city map you can find ways around a lot of the traffic. Stay off LV Boulevard as much as possible and enter the hotels and parking garages from the back or the side.The walking that you have to do inside the hotels is great exercise for those that can do it.
I think it's LV Blvd. rather than the car that's the problem. We just avoid the Strip except for necessity. And you know what, we really don't like the Strip anyway.