I just went to pick up a car from Nationa at LGA and had a whole ordeal renting from the executive aisle since I'm under 25. I picked up a 300c from the aisle bc with executive status and the free days I've always been able to take wtvr I wanted from the aisle. When I got to the gate I was interrogated and told under 25 I'm limited to a Chevy Malibu or standard size car. (Yes I use a corporate code which waives underage as well)
I've never heard that rule before and maybe it's exclusive to LGA. I have rented from national many times in the past w/o issue.i rented a 300c in Maui and a Rogue at LGA a few months ago. They took the car away initially from me but after some threats to call corporate they brought it back. However once getting it it smelled like urine and smoke and I didn't have the patience to deal with their management again. Last time I rent from national at LGA.