I've seen plenty of mustangs get horrible 1/4 mile times. People just don't expect much out of mustangs like they do supra's so you don't hear anyone making a big deal out of it.
And the $$ comparison is worthless. I think it's stupid to factor in the cost of the car. Most people don't buy a car just for a platform, they buy it because they like the car. A true "car guy" will wrench on what he has to make it better or faster whether it be a $800 POS or a $200k ferrari. And "expensive" modifications differ from person to person. Money isn't an object for everyone. The hood on my supra sells for $2k alone, I know guys with $8k rims on their supras... that is peanuts to some guys and if they wanted something basic and fast they could have spent $3k on a turbo kit and fuel system and make 600-700 horsepower.
If you want to start playing the $$ game... If I chose to sell my supra I could get what I paid for it. Some of you that bought your mustangs for $15-20k will have a hard time getting $5k out of it when you sell it. So you are getting raped every day you own it. I bought my 2000 GT for $20k and when I bought the Supra I sold the GT and only got $9k out of it after owning it for 4 months.
*AND* whether you like to admit it or not... the "average" supra will DEMOLISH the average mustang on the street. I've beaten EVERY mustang I've raced in my area including my best friend's 2003 cobra on multiple occaisions. I'm sure that there are quite a few around that could take me, but I haven't come across any yet.
And looks are all relative... I like the looks of mustangs but I get way more compliments on my supra than I did my mustang.
I'm not here to bash mustangs, I joined when I had my 2000 GT and I just got a 65 with the GT package and 4 speed top loader. But I will back up supra's side of the story while I'm here just like I back up mustangs on supraforums when ignorant people make stupid comments over there.