Here's the thing... Everyone wonders how to avoid XYZ car... How about you simply ASK for what you want at the preferred desk. There just isnt any way to avoid the car you dont want all of the time. Its just not going to happen. Thousands of rental locations in the US, different fleets all the time, hundreds of other renters at the same time. Sorry, but the clerk at the desk isnt going to read every single renters personal preferences and assign ahead of time.

BUT -- just take your preferred slip into the preferred desk and ASK for what you want. You'll get it 99% of the time. (Obviously within your class and/or with status).