09 RX8 front bumper
 

do the new 09 front bumpers fit in the 08's and below??

No, it doesn't fit since the headlight has a different shape and the side marker light was deleted.
However Mazmart had an offer earlier for an AutoExe bumper that looks like the '09 and fits the earlier cars: https://www.rx8club.com/mazmart-88/autoexe-new-front-bumper-se-03c-groupbuy-158758/
That group buy offer is closed, but you could ask Paul if he can get you such a bumper if that's the look you're after.