During Wednesday’s news media previews at the Chicago auto show, Hyundai introduced a purpose-built rally version of its coming Veloster coupe, as well as a refreshed and refined Genesis luxury sedan.

The rally car, which is a competition-only effort and will not be offered for sale, is based on the Veloster coupe that was introduced last month at the Detroit auto show and is scheduled to go on sale this summer. The highly modified Veloster will be campaigned by Rhys Millen, the Hyundai team driver, in the 2011 United States Rallycross Championship, the Summer X Games and other events.

Mr. Millen was also responsible for turning the budget-priced Veloster into a race-worthy competition car. Built from a bare Veloster shell that was reinforced with extra stitch welding and an eight-point roll cage, the machine also wears numerous carbon fiber and Kevlar panels, and its interior is race-day spartan. Motivation is provided by a turbocharged 500-horsepower version of Hyundai’s 2-liter 4-cylinder, mated to an X-trac 6-speed transmission and 4-wheel-drive system. Two additional Veloster rally cars, including one built for the 2-wheel-drive class, are also being developed.

Meanwhile, the 2012 Hyundai Genesis sedan receives a wider grille that integrates more seamlessly with the shape of the hood. The lower air inlet has been revised so that the corners no longer turn up in a smile, the slightly drooping headlights are gone and the nose now flows smoothly into the front wheel wells. The rear fascia has also been smoothed over, while the rocker panels turn up slightly in the manner of ground effects, imparting a somewhat more sporting appearance.

The most perceptible changes may lie under the hood, where a revised V-6 and optional V-8 now benefit from direct fuel injection. This enables a compression-ratio increase in both engines, to 11.5:1, from 10.4:1.

The 3.8-liter V-6 receives a 15 percent power increase, to 333 horsepower. A 5-liter V-8, the standard powerplant in the Genesis 5.0 R-Spec, is based largely on last year’s 4.6-liter unit and generates 429 horsepower at 6,400 r.p.m. and 376 pound-feet of torque at 5,000 r.p.m. The 4.6-liter V-8 carries over as well, with the same 385 horsepower rating as last year. Fuel economy numbers for the more muscular V-8 are 16 miles per gallon in the city, 25 on the highway — one mile lower than the carryover 4.6-liter in both driving categories.

The Genesis 5.0 R-Spec will also benefit from more aggressive chassis tuning, coupled with bigger stabilizer bars, larger front brake rotors and revised steering calibration. Subtle styling cues will also distinguish the hottest Genesis from its tamer siblings.

All three engines are mated to a new 8-speed automatic transmission that reportedly improves fuel efficiency.