Avis is generally not so good for the retail underage renter. Granted, there are a few corporate or association contract codes that remove the underage fee, but from what I've seen at least, significantly less than with Hertz, National, and Enterprise.

Before Hertz offered the Underage Coupon and free Gold Family, many Avis and Budget locations didn't have an underage fee- they flat out rejected the underage business. Now they have a $35/day underage fee, and even admitted they still don't really want this business.

Enterprise and Alamo were at the time more popular for the retail underage set, if primarily for their transparency. Yes, you would pay the normal undiscounted $75/day at ORD, for instance, and yes, you would pay the $25/day (at the time) taxable underage fee, for a very expensive one-day economy car rental, but you could add the underage fee at time of booking, rather than at the counter, and know what your final total price would be. Hertz at the time had an underage fee of $27/day, added at the counter, but the main advantage for underage renters was that often Hertz was the best value and convenient for one-ways.

Could of course doesn't mean would. At that time many potential retail underage customers, myself included, assessed the other transportation options available at those prices and walked away.

With Hertz's coupon, it changes everything. Avis or Enterprise may have been nominally cheaper had I been 25, but Hertz will come out cheaper since I'm not.