Penny is holding an extension wire in her hand while working on her computer-book in the Gadget Van, but when her hand is seen pointing at the screen in close-up, it it empty. Then in the following shot the same hand is holding the wire again.
When Penny is using her computer-book to locate the kidnappers while sitting in the Gadget Van, she is holding an extension wire over the book, but her hand somehow moves behind her pigtails (cel layer mistake).