Do i need an ADR for a late night dessert?

[disneypolybride2008]

After the parks close early and afer a TS dinner i want to check out T-Rex, but just order a dessert or appetizer. Is it sooo popular that i need an ADR because it's packed or can we just go? I would only be going to DTD for that so i would hate to not get in. We would be going close to closing time. What do you think? Do you have to give a credit card when making an ADR there?