I haven't installed either, but I honestly don't think there is any significant difference btw the 04 and 05 suspension. In fact, this Acura dealer who advertises on ebay lists the same A-spec suspension part number for 04 and 05 models:Acumen said:Speaking of the A-Spec... I've read a few other posts around here regarding it but still have a question. I have a 2005 TSX and I called the dealer yesterday asking about their A-Spec... They said that they actually didn't make it for the 05 TSX yet and that the 04 model won't bolt on the same way. I've read that the 04 and 05 tsx are the same set up so the 04 A-Spec kit will work on both. This mechanic at Acura told me otherwise. I still think he's thinking of the RSX (different in 04 than in 05). Can anyone shed some light on this for me? Thanks!