As they drive off, Gus is in middle of wondering how he's going to explain the change in the company car to his boss, when they are pulled over by McNab. He tells them the car fit a description and as he's apologizing for his mistake, a dog from the K9 unit jumps out of the squad car and starts barking at the Echo. McNab again apologizes, explaining the dog is still in training, gets the dog back into his car and leaves. The guys then head to the police station where Shawn gives them the serial numbers he'd seen earlier. It turns out the numbers correspond to car parts purchased legitimately by "Bling It On." Still, Shawn is convinced there's something not right at the car shop, so they go back to do more investigating. They find out that a fleet of cars is being shipped to Arizona and as Shawn is receiving a call from Henry, Gus picks up a rim and is surprised at how light it is. But before they can get anything else, they have to go to Henry's. He says it's an emergency.
Of course, when they get there the emergency turns out to be only in Henry's mind, but while there cleaning fish, Shawn puts the case together. Jonny G.'s been smuggling drugs out of state inside car parts. That's why the rims were so light and that's why the police dog barked at their car. Wally's just the fall guy for a bigger drug operation. But when they get back to "Bling It On," they find Jonny G. dead inside a car from a nitrous oxide leak in its performance booster.
The police think it was foul play but have no leads, so Shawn and Gus go visit Wally again, who insists that he had nothing to do with the drug operation and was just the front man for the chop shop. But Shawn comes away believing that not only was he the mastermind behind the smuggling ring, he's also somehow responsible for Jonny G.'s death while behind bars. Wally was easy to catch because jail gave him the perfect alibi and with Jonny G. out of the way, he'd have sole control of the custom car shop and thus the drug operation. They hear that Wally has finally posted bail, so the drug deal is going down today. Shawn remembers seeing the shipping form for the cars. They know where and when, now all they need is backup.
They crash the 21LES seminar, which isn't going well, so it doesn't take a lot of convincing to get Lassiter and Juliet to the drug deal. They arrive in time to catch Wally in the act, with the drugs hidden in the cars. Wally knew that Jonny G. always checked the cars himself before delivery and rigged the nitrous oxide container, knowing it would kill him. With Wally now off to jail for good, Gus can finally finish using his vacation package, with Shawn in tow, of course.