They all had manual transmissions. The Bullit is basically a GT with maybe 5-10 more horsepower and some appearance upgrades. The wheels on the wagon were the Subaru BBS wheels with 215/45-17 tires IIRC, can't remember what tires they were running though. I would say the stock GT will beat the stock WRX (when driven by a professional on a familiar track, of course).
Actually, looking at some other results, the following vehicles also beat the stock WRX:
Ford Escape XLT 4x4, Honda Accord, Civic, CR-V, Chrysler PT Cruiser, Cadillac DeVille, Pontiac Aztek, Saturn VUE, Toyota Camry, and RAV4, among others.
I seriously doubt that the testers at Motor Trend don't know how to drive the car. I've read that in dry conditions, the AWD system can be more of a liability than an asset due to the added weight. Also, according to Sport Compact Car (EVO 7 vs. Stage 0 WRX) the WRX AWD system isn't optimumly-designed for sports applications (tends to understeer instead of oversteer like the EVO 7). The stock suspesion and tires are definitely not designed for racing (I think most people on this forum can attest to that). I also think the turbo lag could contribute to a lower slalom speed, but I'm not sure. Does anyone else have a better answer?
I don't think turbo lag has anything to do with it. My guess is that the wheels/tires make the biggest difference. A jump in 4mph just from bigger wheels/tires would show that they make a huge difference in handling. Consider the other cars are probably on better tires than the RE92s we get stock(especially the mustangs).
Also, both the Bullitt and the Cobra have significant suspension upgrades that the GT is lacking. The Bullitt is 3/4 inch lower than the GT, has higher spring rates, stiffer shocks, and stiffer swaybars, as well as a couple of chassis stiffeners. And wider, stickier, lower profile tires. The Cobra (beginning in 02, I believe) has much of the above, plus independent rear suspension.
I know that until these two models came out, I'd never seen a mustang perform well at all at autocrosses. OTOH, both of these models have posted pretty respectable times. But then, they're sort of the Mustang equalivalent of the STi. Comparing it to a "normal" WRX is a little bit apples-to-oranges.
I also believe the RE92s contribute heavily to the WRX's handling woes. Replacing those with rubber comprable to what the Cobra / Bullitt are wearing would even things out quite a lot, I think. Look at how much optional tires improved the wagon's slolam speeds- and most reviewers who have driven both agree that the sedan handles better than the wagon. I suspect that with improved rubber, the sedan would be at least 1-2 mph quicker than that wagon's speed, and certainly quicker than either of those ponycars.
And if you took the suby equalivalent of all the suspension improvements the Bullitt / Cobra have- stiffer springs and shocks, chassis stiffening, lowering, and stiffer swaybars, the WRX would really nuke the mustang. Let's hope the STi, when it gets here, lives up to that standard.
I dont have any experience with this because I dont have the car yet but Ive heard the WRX has some body roll to. Could that affect it also? I guess I agree with most of you in that a WRX with the equivalent suspension package of the Bullit and better rubber would perform better.