Ford Escort - Most successful rally car of all time.
Ford Sierra RS500 Cosworth - highly successful in European and World Touring Cars in the 80s and early 90s and winner of the 1987 World Touring Car Championship.
Audi Quattro - Needs no introduction, or Ford RS200 for that matter. Add Group B spec, and you have something that will still show most if not all hot hatches the way down the road even today.
These are just three examples, but all have successful and proven racing background and history, all have their place in history and all are now rare, sought after and will only appreciate in value. The RS4 does not fall in to any of these categories, rose tinted glasses or not. It is a heavy thirsty lumbering beast with note which in reality is slower than its claimed power figure would suggest.
For sure, if you compare new vs old, of course a 20/30 year newer car with twice the displacement, twice the number of cylinders and valves has got a good chance of being "faster". That however is not my point. My point is that the RS4 has nothing to offer to make it iconic and if you spend similar money on something which was and is still iconic today (Evo), you will get from A to B faster every time with as much space, as many toys and with a much bigger smile on your face. Or spend out on an RS6 V8, add a milltek, intake, remap etc for less money and with the extra space, toys and 100+ extra bhp, enjoy passing an RS4 getting death like it is parked.
I have no idea where you're getting your info from - they're your opinions which you are welcome to!
I think you're mistaking what's being said. Your suggestions are great for showing off on a drag strip in front of your mates, but overall (and yes my opinion), you cannot compare an Audi RS4 to an old Ford or an Evo! It's a luxury saloon which has fantastic handling/grip/acceleration all tied together in a reliable and more unique package - End of for me.
. Iconic means that the car has achieved something. RS4 has never achieved anything other than failure to make 30mpg on a good day 
!!!