Filming for the new "Transformers" movie has been blowing up Chicago, much like the Bears had done for the first three weeks of the NFL season. On Sunday they put their undefeated record on the line in Detroit, home of automakers and star receiver Calvin "Megatron" Johnson.

It didn't turn out well. Bad Jay Cutler showed up. So did big, bad Ndamukong Suh. Ditto for Reggie Bush. Add it up and it means the Bears lose 40-32, falling to 3-1 and into a tie with the Lions for the NFC North lead.

The Bears did their best to make it interesting, spotting Detroit a 40-16 lead before charging back with two touchdowns and a pair of two-point conversions.

"The character we have in that locker room wouldn’t let us stop," Cutler said. "We kept fighting back. ... If I tightened up in the first half, hopefully we’d have a different outcome."

So who played like a powerful, city-stomping machine, and who looked in need of serious repairs? We put the key figures from Sunday's game into three categories: Optimus Prime (intimidating sem-itrailer truck), Bumblebee (slick sports car) or broken-down mess (lemon).

Chicago Tribune contributed to this report.


Lemon: Bears special teams

To no one's surprise, Devin Hester kept returning kickoffs that he fielded deep in his own end zone. To everyone's surprise, he had a hard time getting back to the 20-yard line. The special teams also surrendered a long punt return in the first half that led to a Lions TD.


Truck: Julius Peppers

The Bears' star defensive lineman was practically invisible the first three games of the season. But he wound up with a respectable four tackles and forced a Lions fumble that turned into a Bears field goal late in the first half. So that's something.


Sports car: Reggie Bush

The Lions running back twisted, leaped and dashed his way to 139 yards rushing and 34 receiving, including a touchdown. He was the difference-maker in this game, much more so than Calvin Johnson. The Bears just had no answer when they needed to stop Bush.

Their words: "When we don't tackle the way we need to, that shows what [Reggie Bush] can do." —Bears defensive lineman Corey Wootton


Truck: Alshon Jeffery

As Martellus Bennett would say, it was Jeffery's turn to "channel his inner Brandon Marshall." He showed great hands, coming down with a 44-yard bomb and later a TD catch in heavy traffic. He also stiff-armed a would-be Lions tackler on a 27-yard run in the second quarter.