ASHBURN, Va. — When Willie Smith became the only undrafted rookie to make the Washington Redskins opening day roster, he celebrated by spiffing up his 2000 all-white Crown Victoria.

“I noticed that he had got his windows tinted and he had gotten rims on it,” running back Roy Helu said, “so I just joked around and said how he’s changed ever since he’s made it big-time.”

Helu has kept it up all season, making up stories about Smith getting accessories like subwoofers and satellite radio. When Helu told the story to reporters this week, Smith was beside himself.

“Oh, come on, Roy,” Smith bellowed across the locker room Wednesday. “You told them I got big-time? Got tinted windows?”

The truth is that Smith only got the rims — the car’s windows were already tinted — and that Helu does the shtick because he says Smith is actually the opposite of flashy. Besides, a newbie at the fringe of the roster doesn’t need to be spending big on his car.

For most of the season, there wasn’t much reason to tell such stories about Smith — that is, until Trent Williams was suspended two weeks ago for the rest of the year for violating the NFL’s substance policy. Now the left tackle from East Carolina is protecting Rex Grossman’s blindside, having made his NFL debut against the New England Patriots before getting his first start in Sunday’s win over the New York Giants.

That means he’s already faced two monster pass-rushers, Andre Carter and Jason Pierre-Paul. Now he has an assignment that looks even more daunting: On Saturday, the Redskins host the Minnesota Vikings and Jared Allen, who needs 5½ sacks over his last two games to break the league’s single-season record.

It has mismatch written all over it.

“I’m going to have to go out there and just be tight on everything and fundamentally sound, just to even have a chance to block this guy,” Smith said, “because he’s just that good.”

At least from a big-picture view, the results from Smith’s first two games are surprisingly good. The Redskins scored 27 against the Patriots and 23 against the Giants, their best two-game points output since September.