I have rented several times at MCO with Avis. Granted, you can't pick cars but when you rent a full size you get a buick century, a premium you get a buick lesabre etc. so picking a car doesn't help unless you can pick a upgrade. Color is not an issue with me. Spouse drives for no extra charge with Avis - just make sure their rates are competitive. If you aren't geting the lowest rate these little extras mean nothing. Don't know if you are eligible but I usually can get an Avis rate that is very competitive using the AARP code A35****. Also try using the employee code of A153700. Obviously you can't follow through on the employee rate if you have no proof of employment but I find it useful to check what the "lowest" rates are to see if my discount codes are
good deals. Goood Luck!