Originally Posted by pinniped

Found a code that behaves rather strangely so YMMV even more than usual on this one.

Without the code, my best option for a 3-day rental this weekend at ORD was $137 all in for an Alamo full-size plus 600 Southwest points. (Yes, full-size was less that mid or standard and equal in price to econ and compact.) Costco code.

With the code, it drops my rate to $106 all in for a midsize SUV, no option to purchase 600 WN points for $5-6, and the full-size car went up to a somewhat higher rate. (Like $150 all in.) There's actually an alert on the confirmation page that I cannot add an airline number because this contract doesn't allow it.

Since I don't particularly care what kind of car I get as long as it's bigger than a midsize, and since the points aren't worth anywhere near $31, this works for me. It's advertised as a $25 off code and it's netting me about $26 off, albeit in a different car type.

Code is AD8698SDF. I stacked with the Costco contract ID. When I remove the Costco ID, I have the option of a $116 rate that includes the Southwest points. Since that's basically breakeven on the value of 600 points, I'm booking this one without buying any points.

Anyone else ever seen the Costco contract ID tinker with your ability to purchase airline miles/points with your rental?