Items such as the rear sunblind [a godsend, IMHO!], sat nav and cruise [also nice....] are major items. They may not look it, but the wiring involved in, perhaps, the sat nav system, would entail replacement of a considerable portion of the vehicle wiring loom and more, possibly invalidating the vehicle warranty.
The rear sunblind would require a new parcel shelf assembly and the switch pack fitting to the lower dash area below the Climate Control Pack, together with the sunblind assembly. This would be very expensive!
Lesson to be learnt? Spec your car as you want it form the factory and no second thoughts!!
Nick - if you [or anybody] requires an MG accessory brochure - or indeed any brochure, then please conatct me by email and I will endeavour to get one to you8)