The na version is a 3.2 the srt6 is 3.2 supercharged. Relay should not be a concern there is a DIY no cost fix should work. I all know is there is stereo with and one without nav. ?AUTO OR MANUEL TRANNY. Color, coupe are roadster ALL THIS INFO IS ON THE Forum. YOU CAN SPENDS HOURS on the forum researching info about the xf. If you want speed and a auto trans get srt6, if not the na are also quick and insurance should be less. But u can spend alot of monies on mods trying to get the na to stock srt6 speed and it has not been done yet, if even possible would it still be a good dependable daily driver? I think not. Get one u will love it. Danny