Blooper

When JB and KG borrow the car from their friend, it clearly has stickers on it advertising the pizza business. During the car chase scene, the stickers are completely non-visible. (The reason there are no stickers visible in the car chase is because the shot of them falling off was cut. This can be seen in the deleted scenes on the DVD).

When JB is in the vent at the Rock And Roll Museum he talks to KG on his radio but KG doesn't have a radio when he shows up.

In the Boardwalk scene where Jables meets Kage, you can see a girl with a Mohawk and her friends pass by going in the same direction twice.

At the end of the movie, where JB and KG are thinking of what song to record, the white pick in KG's guitar disappears and reappears as the angle changes.

There is a typo on the DVD in the deleted scenes. It says "KB (not KG) shows JB Maximum Overthruster".

The "pick of destiny" is said to have disappeared for centuries, only to turn up in the hands of Robert Johnson at the turn of the century in the American South. However, Robert Johnson did not play the guitar using a pick - he plucked the strings with his fingertips.

When Jables and Kage are power sliding their way to safety in the rock 'n' roll hall of fame, you can clearly see that Kage is wearing knee pads.

When KG and JB are driving, especially during the chase scene, it is very obvious that the car is on a trailer and being towed and not actually being driven. When the background shows that the car is pulling over to the curb, or turning, the wheel stays straight and does not rotate.

When Lee is watching JB and KG on TV evading the police on TV, the TV station shows camera angles of the police chase that would have been impossible to get even with a helicopter.

In the showdown with the Devil, after JB and Kyle challenge him to a rock off, and he starts to scream "FUCK!", he turns around and you can see a white strap of elastic that holds some of the hair on his lower half on.

Despite the movie taking place in the 90s during the band's formation, the check from KG's mom is dated 6/6/00.

Most scenes involving the playing of guitar are unsynced. The most noticeable is the "Beezleboss (Final Showdown)" scene when Kage starts playing the audio has changes in the guitar chords, but KG's hands aren't moving at all.

When the duo's car jumps the car between the police cars, the wreckage of a movie camera, which they land on, is clearly visible sliding away in the foreground.

When JB and KG cut through Downtown East Baker Parkway, a camera car is visible on the interstate behind a swerving tan-colored car.

After the duo smashes through a Downtown East Baker Parkway sign and get over onto another freeway, a cameraman can be briefly seen on top of a bridge.

The camera's shadow passes beneath KG as he plays the lady leg-shaped guitar in JB's dream sequence.

The map shows Hollywood, Florida in the northeastern part of the state, near Jacksonville. It's actually in southern Florida, near Miami.

When young JB leaves home and a map is shown with an animated line following his travels, the town "Charlotte" appears on the map twice, in both North Carolina and South Carolina. There is no Charlotte, South Carolina, the place marked on the map as "Charlotte" in SC is about where Greenville, SC should be. All other towns marked on the map of the country are correct.

During the scene showing the map, the location of Norfolk, Virginia, is incorrect. It is shown as being in the middle of the state, but in actuality is located on the coast of the state.

Before the fight over who uses the pick at the open mic contest KG says, "Jack wait!" to JB.