There are angled connectors. If you select one that only has DC voltage and no data connections there will be less risk of the cable being an antenna that spread any RF hash out from the scanner or a computer if it's connected to one.
See to that the angled part will have the cable going down, the bigger part of its connector are facing right. Be sure to mark this cable in some way with tape or a label that says it is NO DATA, so you don't try and use it when programming a scanner or other devices.