No, the Fastlane configuration has been designed to provide customers with a flexible mobile workspace while optimising the Hidrive production process to facilitate a fast (4-week) turnaround from order acceptance to installation. The fixed specification is what enables this.
However, Hidrive has well-earned a reputation for manufacturing service bodies tailored to meet customer requirements so if a customer wishes to fit accessories outside the scope of Fastlane they are free to do so, on the understanding their build will move to the usual Hidrive lead time.