Picking up on Deb's response... the park
ECVs require you to flip a switch to go in reverse. Offsite rentals' throttles allow you to go forward by holding the par to the right and reverse by holding it to the left. Sorry, I can't explain it as easily as riders can actually do it.
And, Deb - were you happy with ScooteRama? Not that I have time to change my mind at this late date

but I e-mailed them some questions before I rented and I was happy with the responses (especially the armrest issue

)