You wouldn't be able to power it directly from the cigarette lighter, but it would not be tough to hack up a regulator (Google LM7805). This puck is probably going to have a RS-232 NMEA0183-format protocol for an output, so you would have at minimum use a serial to USB adapter.

Easiest would be to build a custom cable with a 9-pin D-sub serial connector, 5V regulator and lighter plug. Then you'd plug the serial connector into an off the shelf USB adapter. Not the cleanest. I'd probably build a USB interface into a small box and use the USB 5V to power the puck, just completely eliminating the lighter plug option. You could get a commercial USB adapter and pull the guts out for your interface, for example. This would take a little soldering but nothing exotic.

Is it worth it, depends on how much you want to tinker. It's going to be more rugged and easier to mount externally but it's not necessarily going to be an more accurate or quicker than your other GPS receivers.