Seen rally cars on the road heaps of times, going between stages, whole heap of them went through the tunnel late last year in Perth, caused a few surprises when three evo's and an MY98 pop out of the tunnel and get air on the way over the overpass just outside the tunnel.
They're light as hell, and much with the fun to drive >

That turbo isn't all that big, but then again, I wouldn't want to see an evo or a wrx with a GReddy T88 strapped to it (Think of the lag kiddies) (Sidenote: MY98 (1998) WRX STi, came shipped stock in Australia with a GReddy T66 turbo, making for 205Kw (275hp) at the wheels, the most powerful PRODUCTION WRX STi to date!)
There is a ex WRX STi rally modified car at one of the Subaru dealerships in town, and if you get the right sales person to talk to, they tell you quite a bit about how it's all set up (And they DON'T give out dyno sheets, I asked!)
EDIT: After talking to my mechanic friend, he's given me some pointers as to how Ryousuke could estimate fairly accurately the hp of the R32, and it's nothing to do with the exhaust, but the short race beforehand. It's all to do with the power of the FC3S, acceleration and so on, plus observing the car behind you, how easily it can keep up, turning, down to the basic motion of the car. After going on a circuit race with him once, I realised just how accurate even his handling of the car is, but he's build his car to suit him, almost from the ground up, and has been driving now for over 8 years, so the handling shown in ID is possible in real life, all factors aside... All it takes is practice! /EDIT