Remotes Unlimited now stocks AutoPage keyfob remote XT-12, which is a 2-button remote used on the C3-RS-601 remote start system. The FCC ID on this remote is H5OT52. See this remote at the following link: http://www.remotesunlimited.com/catalog/product_info.php?products_id=1835
As with most aftermarket alarm system remotes, the AutoPage system model C3-RS-601 can be programmed to accept a new transmitter using the valet (over-ride) switch.