Anybody got an explanation?

Subscribe
Budget partner offers 25% off. When is it factored in?

A recent example going through a partner I booked it using the BCD and
COUPON# (25% off and X points per day). Base price of car is $197. Grand total (rounded) $239 includes $42 taxes/fees.

I immediately did a test ressie for the identical location and times, but left the BCD - COUPON areas blank. Base price of car is $174. Grand total (rounded) $217 includes close to same in taxes.

I called about this. Later, not knowing they were doing so, I received a modified reservation showing a total of $217.

Today I did a test ressie on the above two and got the same info.

Am I missing something? $197 base - 25% with taxes would come out close to $200.