A perfect example of the attention to detail required in street cars can be seen in Opera's Nissan 350Z, where chassis glue (a la Lotus Elise and Exige) is used to stiffen things up in the rear, as opposed to welding. The glue changes the harmonic point of the chassis, which actually makes the suspension noise quieter than stock.
A welded rear end results in resonance in the cockpit that is unacceptable in a street car. The two cars we've been citing happen to belong to two of the most important names in car video game nerdery. Kazunori Yamauchi and Satoru Takasugi are the guys that made it possible for any car lover with 50 bucks and a PlayStation to drive whatever car they lusted after with virtually reckless abandon.
That's why the other place you can find Mr. Yamauchi's 350Z is right next to the Opera Performance S2000 in Gran Turismo 4's "Tuner Garage." The DC5 RSX belongs to Takasugi, one of the track designers of the same legendary game. He's the guy who spent more than a month at the Nrburgring with a tape measure and enough Red Bull to kill an actual bull, making sure the track was dead accurate. All three cars are gathered here for a brief reunion, thanks to the cooperation of Yamamoto-san at Opera and a couple of guys who eat, sleep, and breathe at the game manufacturer, Polyphony, and thus don't need their cars anyway.
After stripping the cars down to bare metal and skewering them onto the rotisserie, custom crossbraces were fabricated and fitted to both roof and undercarriage and welded to newly reinforced structural members of the existing body.
In the RSX, a unique brace makes a giant "X" across the roof and is supported using custom-formed metal triangles. Like the other braces found throughout the chassis, these have been drilled through with various-diameter circles and chamfered for strength. The brace was later covered in a thin layer of plastic, and coated with fabric to match the rest of the roof.
The engine comes out with everything else imaginable in the front end. The engine will be replaced with one that we're only allowed to call "special". | 
The chassis is braced before the roll cage is welded in. | 
Note the additional weld points to the chassis, as well as the extensive triangular bracing on the roll cage. The cage has more points than we've seen in a long time - we stopped counting at 16. |
In an attempt to have the most accurate templates possible to weld atop the stock pieces, Opera Performance purchased a number of frame pieces directly from Honda and Nissan and simply fit them atop the existing framework. The new pieces were cut to ensure they were no larger than necessary and that only weak areas such as bends and joints would have the additional reinforcement. The pieces were bolted on and welded into place. As is traditional with Yamamoto-san's philosophy, very little work was performed on the engines of each car. Yamamoto took a page from the N1 book when it came to engine design. Though each engine is torn down completely, it's only balanced and blueprinted before it's put back together in an effort to decrease friction. The Former N1 car creator uses weight as his weapon, not high horsepower. This allows his cars to keep the same broad powerband as stock yet still accelerate ferociously.