INDIANAPOLIS Retirement is only way to go for Al Unser Jr.

He won two Indy titles and two CART points championships.
INDIANAPOLIS (AP) -- Al Unser Jr. gave his heart to racing. When he felt his passion was gone, he had only one choice -- to get out of the car.
On Wednesday, Unser, a two-time Indianapolis 500 winner, announced his retirement from the sport that defined his life and his family's legacy.
"I've had a great career," he said. "It's been a challenge, been hard to follow in the footsteps that I've followed. I feel I upheld the Unser name quite well."
Unser, 42, was one of open-wheel racing's brightest stars and biggest names during a turbulent time. He stayed with Roger Penske's team when the Indy Racing League and CART parted ways in 1996, then switched to the IRL in 2000.
Professional
Through it all, Unser was one of the few players who seemed to stay above the spat. He won two Indy titles, two CART points championships, a combined 34 races in 21 seasons and remained a favorite of fans and drivers.
"You knew if you were racing against Junior he'd try to pass you cleanly," former driver Scott Goodyear said.
The Unsers always considered racing a family business.
Junior started in go-karts at age 9 and learned his trade from some of the best. His father, Al, is one of three drivers with four Indianapolis 500 wins.
Junior's uncle, Bobby, won three times at Indianapolis, and Junior's two victories gave the family nine in the biggest race in open-wheel racing.
Two of Unser's cousins, Robby and Johnny, also raced at Indianapolis.
But after 33 summers of racing, Junior still couldn't leave the track completely.
Newest career
His newest career -- serving as an adviser for Patrick Racing, his team, and a driving mentor for his 21-year-old son, Al -- begins this weekend at the Argent Mortgage Indy 300 in Kansas City, Kan.
Team owner U.E. "Pat" Patrick has not chosen a replacement for Junior.
"What scares me is going to Kansas this weekend and watching Little Al get out there," Junior said. "Hopefully, he can follow in his father's footsteps and his grandfather's footsteps."
The IRL has lost two of its most prominent drivers in 13 months. Michael Andretti retired in May 2003 at age 40.
Andretti also grew up in a racing family, endured the pressure of living up to his famous father's achievements and left the sport earlier than some expected to focus on his ownership in Andretti-Green Racing.
Michael's father, Mario, won the 1969 Indy 500 and 1978 Formula One title.
The two sons were continually linked, though, sometimes referred to as the IRL's second generation of stars.
"Al is one of the best guys that's ever driven a race car," Michael Andretti said in a written statement.
Final season
This season, Unser has dealt with a litany of frustrations.
He worked for several months to find a ride after breaking his pelvis last October when he was thrown from an all-terrain vehicle in New Mexico. After months of rehabilitation, Unser finally signed with Patrick Racing in March but missed the first three races of the IRL season.
In three starts, Unser's best finish was 11th, and last weekend at Richmond he was the slowest qualifier in the field. Unser finished 22nd in what proved to be his final race.
"I'd still like to see him racing, but if he's not happy, he should get out," his father said. "He's proven he's a champion."