To be fair, the 2004 USDM STI weighed in at 3,263lbs. 2015 USDM STI weighs 3,386. 130lbs over 10 years honestly isn't that much; especially compared to other vehicles. While I do agree that the size has definitely gotten on the fat side, the weight surprisingly hasn't increased as much as one might think.I could build my perfect STI from the Fuji heavy industries parts bin, all the good bits and pieces that Subaru and STI developed, and none of the superfluous luxury barge stuff that now fills the STI that makes it a fat pig.
2003 Evo VIII: 3,263 | 2008 Evo X: 3,517
2005 Corolla: 2,530 | 2015 Corolla: 2,875
2005 M3: 3,415 | 2015 M3: 3,540
2005 Civic: 2,441 | 2015 Civic: 2,749
Some cars haven't put on much weight, and others have put on quite a bit. There are a few out there that have lost some weight over the years, like the Camaro... but cars have mostly gained.
I'm all for decresing weight. CF driveshaft and roof, along with a few other small things here and there. If the vehicle were a bit smaller and introduced some CF components and came in with a weight of like 3,100lbs, that'd be awesome. But one can dream. Cars are just going to keep getting bigger unfortunately. Nevertheless, I'm happy that the STI has only increased in weight by 100lbs over the past decade, especially considering how much bigger it is compared to the GD.