I'm struggling with this one. I love the design of the cars. I despise that it's another premium option for sale. My thought is that the more that people start to buy rides in these cars, or buy that special park to park express bus service, etc., the more WDW will eventually cut back on the "free" transportation like the buses, boats and monorail.
Speaking for myself only, I scrape together money every year to go to WDW for 4-5 days. It's expensive enough as it is, and I don't even do table service meals. One of the main perks about going there is that you don't have to get a car. You can let them do all the driving to different places on property, and as long as you can deal with (sometimes) longer waits, you're really all set. No upcharge. It may not be a perfect system, but it works for me (except for the water parks new bus system, with connections--epic failure
).