Yes, you can use OEM LCI taillights on an '08 sedan, but you have to swap out your trunk lid. If that's too much to swallow, then you can buy pre-LCI Black Line lights for a slightly different look. They are OEM as well.
'09 E92 M3: Space Gray, Black, Carbon Leather | ZTP 2MK ZPP 2MT 6FL | link 1 / link 2
Mods: M Performance exhaust | ZCP retrofit | Euro airbox | GTS DCT flash | JPN 240 ECU flash | Euro LCI taillights | CRT lip | OEM alarm retrofit | Space Gray bumper plugs | BMW Performance: Mk. II spoiler / Mk. II non-electronic steering wheel / mirror caps / front grilles / side gills / intake louvers / emblem