Unless they eliminated the tranny drain bolt in the '08, It's not necessary to drop the pan. I'd never have a flush done, and would never even walk into an Iffy Lube, but that's just me.

If you absolutely don't want to DIY, then I'd recommend taking 6 quarts of fluid to a quality independent shop and have them do 3 drain-and-fills. Use the fluid speced in your owner's manual (T-IV, unless they changed to something else later on). Again, JMO.