OK I have not seen this yet so here is my method:
Lay the brick behind the battery
Lay the coiled cord toward the front
Insert J connector and lay the cord snug in the front corner along the weatherstrip
Draw the extension cord same along the other side and close the hood
Side view ready to plug in
The extension cord shown I believe was #16 wire. After close to an hour the wire was fine but the connectors became very hot. It is an old cord and probably worn connectors. My #12 wire extension cord fit the slot just fine so I have to recommend the heavier cord. I have used this HD cord for 6 hours continuous with no heat issues.