i dont think the heated mirrors is a diff i have a premium rsx, 2002 and i have heated mirrors on mine...(it was new when it first came out, on backorder i had to wait 4 weeks, so if i have heated mirrors...i think everyone should...but mine is in CDN if the spec's on that are any diff) i asked about future changes i was told the only change for the 2003 would be that they would attach the gas tank thing...where u put in the gas in, that piece that u unscrew to refule your car mine is not attached to the car, they said they would add a string attaching it i dunno if it happened...doesn't make a diff if it did though..and he also said that this would be the model of the car before the reshape for 7 years...so whats that take us to...2002+ 7 years....2009 model..will be the reshape..or new design, thas what i was told atleast
they usually change 1 car every year, for 2004 the new TL was introduced..i would think for 2005 the RL will be reshaped and brought more up to date style wise and for 2006 a new 1.7EL shape will be introduced, 2007 and 2008 maybe the MDX....or NSX...not sure just guessing and then maybe the RSX in 2009 they usually do 1 per year, so your fine for a few years, about preformance i have no idea...
as for changes with the RSX ask the dealer they usually will have a idea...but it might be to early for that