I'm new to National/Emerald club and have a question regarding a reservation.

If I book Emerald Reserve for an SUV, and when I arrive to pickup see a suitable vehicle in the EA that I would rather have, can I take it and then only pay the Emerald Club Midsize rate?

and vice-versa

If I book Midsize through Emerald Club and when I get to EA I do not see a suitable car, could I ask for something different and then at-worst just pay whatever my corporate rate is for the class I want?

Thanks for your help!