I often rent from Enterprise when I travel to MO. They are quick, efficient, and friendly at the airport. They offer all the upgrades, bells, and whistles, but explain them carefully along with any additional costs. They are not pushy, though, just informative, and don't pull any gimmicks if you decline. The big cost of renting a car at KCI comes in the taxes, which are usually half of the total rental cost. The taxes for things like arenas and facilities never touched by a traveler are a huge ripoff, but Enterprise has always worked well for me.
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