Hey Champ,
That place likely always will be a problem since it is actually part of the Flamingo Wash (for more information see the LVA QOD Archives From April 4, 2008). I remember years ago on the news here in Los Angeles seeing cars floating where there was flooding in the parking lot! It was just bad!
It really would be a decent (and the right) thing for The Quad (or CET) to put on their website (unless I missed seeing it) a notice saying that this (flooding running through the Imperial Palace/Quad parking lot during rains) has been going on and that people should be aware so that their cars don't get possibly damaged.
I actually should have made the title (and now I'm going to partially change it) say "Heavy Rains Coming Could Again Cause Parking Issues At The Quad."
And I now have found Video (on Youtube) of the Flooding In The Imperial Palace garage. It is found at: https://www.youtube.com/watch?v=PCZyCqge6G8. This was at least uploaded in December 2010 (you can see a sign for "Human Nature" at Imperial Palace in the Video at just before the 1 Minute mark in the Video).
I also found an article about this flooding issue at Imperial Palace from 2004 in the Las Vegas Sun which can be read at: https://www.lasvrgassun.com/news/2004/apr/06/flood-problems-plague-strip-hotel/. The article even mentions that Imperial Palace has no intention of making the parking garage any less flood prone.
And also at least in the 1970's, this also was a problem with the Caesar's Palace parking lot. I don't know if that is still the case, but that should be looked into. There was a major Flash Flood that went through the area on July 3-4, 1975. A bunch of cars got flooded at that time.
RecVPPlayer