Just got back from the dealer and checked out the covers. The new '09 and later 4pt uses 4 SMALL covers. The large fit but they will be loose and rattle, where the small fit tight on the mounts. Hope that helps guys! And for the OP, looks like you need 1 large and one small per side, even the catalog is confusing for '08.

 

Why mess with them when you can use the FBI kit!? They literally disappear. I use mine for a detachable luggage rack.

http://www.roadglide.org/showthread.php?t=5297

quick google search of the setup installed. Just need to be careful when opening the saddlebag lids so you don't nick them on the hardware.

Stock HD config is nasty.

 

Mine are the large ones. I hope this helps!