I just picked up the FXR4 Service Manual (PN: 99480-00) from H-D for about $40.00.
Don't waste your time or money.
While it is called the "Official Factory Manual", it is a service manual supplement that does not contain any information pertaining to the following sections: ENGINE, FUEL SYSTEM, ELECTRIC STARTER, DRIVE, TRANSMISSION, or ELECTRICAL. Each of these (IMO, critical) sections of the service manual only state, "All 'Specific section' service procedures in the current FXR2/FXR3 service manual also refer to FXR4 motorcycles..." To be fair, it says Supplement on the top, but that was not legible on the H-D website where I got it.
In short, just buy the FXR2/FXR3 service manual, as there is nothing in this supplement to warrant the $40 price tag. Although, I haven't yet shelled the additional $40 for the 2/3 manual - could be that it just refers you to a more previous manual also!!
Guess I should've known there was a reason that Harley manuals are all sealed in plastic in the store and you can't read them before you buy them.