Early this year we booked Silver Basic for our Feb/March trip and it included an additional driver for free. I was worried when I completed the Alamo Save Time (or whatever it is now called) and the paper work was quoting for the extra driver. Roger assured me everything would be ok and it was. We went straight to the garage and the paperwork was sorted at the exit barrier. The lady there at first wanted to charge me for the extra driver and I had to explain it was already included even though it didn't say so on the online check in paperwork. Fortunately I had my original USCarhire voucher which did say one additional driver included which she eventually accepted.
We are visiting Orlando this November and again have the Silver Basic with the additional driver included for free. I just hope it runs smoothly this time too if we go straight to the garage!