If you fit into the weight class, this
ECV would be my choice -- the Pride Go-Go Elite Traveller with the optional 18AH Battery. Battery life is probably the Achilles heel of using a
scooter all day, and the bigger the battery--the better. I had this same Go-Go model with the standard 12AH battery, and it didn't last during one extra-long day at Epcot. I parked somewhere and plugged in for 1-1/2 hrs.
You can buy an optional second battery pack and keep that available in your van. If your first batteries are getting low, swap out the battery pack. That is what I did later, and it helped on those long days.
The Go-Go is very light and compact. I had a minivan, and I removed one of the second-row seats to make a space. I lifted off the ECV chair, removed the battery pack, and the remainder of the ECV went in nicely. (The remainder of the ECV was about 50 lbs.)
No matter what ECV you choose, plan to replace your batteries once a year. Although the charge meter on year-old batteries will be high once charged, those batteries will "run down" much faster than fresh batteries. If you're going on a special trip, think about replacing your batteries just for that trip.
Don't go to a medical store for your scooter or your batteries -- way overpriced! Additionally, I looked up the Go-Go on
Amazon and the price was good, but there was no listing for the optional 18AH battery or the extra battery box. As far as Amazon was concerned, you were buying something in a brown box, nothing more. I would recommend Spinlife.com for the best price/customer service for the ECV. I am on my second ECV, and I bought both from SpinLife. I had conversations with people there. I asked questions. They had answers for me. They also had many brands of ECVs to look at, to fit your needs best. As delivered, the ECV was in a big box and mostly assembled. I put it together myself, very easy.
As far as replacement batteries, you could order them from SpinLife, or Google the internet. You'll find amazing price differences from place to place. Take a pic of your batteries, so you see how they are labeled, and how they match up with batteries for sale online. It's important b/c the Go-Go batteries are airplane-safe, and that's what you want for replacement. You could mistakenly order batteries that weren't air travel-worthy. The description info will say which kind of battery it is.
Go-Go Elite Traveller from SpinLife.com:
http://www.spinlife.com/Pride-Go-Go...Scooter/spec.cfm?productID=78301#.U_EWzkjDykg
SpinLife--All ECVs and Accessories:
http://www.spinlife.com/category.cfm?categoryID=4