I'm leasing my GT-T through them. Talk to JimBo he'll take care of you.
7heavn has summed it up in a nut shell....great way for people who can't budget themselves!
Prosperion give you a shell card, so if you're VERY picky on fuel brand you might wanna take this into consideration.
EDIT: oh, good thing about shell card is u can use it to buy oils for your car like g/box oil, motor oil, diff oil :uh-huh:
Also service is bundled up...u call them, they come pick up your car and bring it back