From 2002-2007, Buick Rendezvous SUVs were equipped with a factory keyless entry system that uses a 4-button remote with FCC ID L2C0007T. The original keyfob had a rear function button icon that simply had the word “REAR” on it. This remote is identical to the L2C0007T remote that was used on Buick Century and other sedans, except that the sedan keyfob had a trunk button icon. The remotes are fully interchangeable.
See both L2C0007T 4-button replacement remotes at this link.
Note: Whether or not a keyfob is user programmable has nothing to do with the remote. It is a function of the system in the vehicle. Some control modules can be programmed to accept a new remote and some require programming at a dealership with a special computer tool. So, for instance, on all Buick Rendezvous SUVs, the factory keyless entry system is user programmable, but on Buick Century sedans dealership programming is required. This is true even though they use the same replacement remote.