GT2 has the actual Pikes Peak course (and the Suzuki Cultus and Escudo Pikes Peak cars), while GT3 just has the Escudo Pikes Peak car. Easy to understand the confusion
There was a Pikes Peak track made for SCGT and it was converted to rFactor. The dirt physics in rFactor are crap and the cars that are avaliable to run on the dirt tracks are equally crap. But if you want some kind of PC semi-sim Pikes Peak in rF is as close as it gets. There have been no other Pikes Peaks made for sims as far as I'm aware, if you're into arcade games then I think some GT and CMR games have it.
Back on topic, GT2 is the only game I can think of that has the Pikes Peak course. I don't think there's a decent sim out there that has it but I could be wrong.
The new DiRT game has a good version of Pikes Peak, and somehwat accurate, but you have to get far in the game to run the entire course. Has all the good hillclimb cars too (and huge hillclimb semis).
Haven't played a better version of it anywhere else. I tried the conversion for rFactor, but yeah it is crap as ajp71 said already.
Although this car was the absolute best for cheating, I started using it on the 2 hours of that city track 'endurance' race and because I cooked the tyres so quickly I didn't bothere pitting and basicly drove the full time flat out scraping around the walls basicly doing faster lap times than with good tyres. And back in those days, it somehow was still set to 99 laps, clearly wasn't enough as I completed all 99 laps in 1 hour and 53 minuits IIRC.
Sorry for the uselessly useless post, but in reply to why the car is so famous I figured i'd post up why it is so, to me anyway.
My favourite Escudo trick in GT2 was when you had that oval enduro to do (worked in GT3 with the mega-oval races too): use a rubber band to hold the right analog stick flat to the floor, let the car take off, get it to top gear, go do something else (but periodically check that you're facing the right way ). Gold.
Was that 5 mile long mega-oval in GT2? The one in GT4 basically has a long line of dips in the turns if you try to run anywhere near the top paint line, making any car almost impossible to control.
Don't recall actually, it's been at least 8 years since I played GT2. The one in GT3 was nice and flat and felt about 10 miles long. I've not given GT4 much of a thrashing (somehow they made the physics suck more than ever - if I can't get a 400hp Charger sideways, something is seriously wrong).