The fuse box is located under the drives side footwell area. You will have to get on your back on the floor and look up. No need to remove any dash components. The fuse box has a cover on it that looks like this: Here is the fuse box with the cover off: Here are some helpful links related to the fuse box:
Fuse Layout Chevrolet HHR 2006-2011. Cigar lighter (power outlet) fuses in the Chevrolet HHR are the fuses β7 (Rear Power Plug (Panel Van Only)), β12 (Rear Power Outlet (Panel Van Only)), β29 (Cigarette Lighter) and β30 (Power Outlet) in the Engine Compartment Fuse Box.
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