G'day Lang,

As far as I'm aware there aren't any longer cable options, sorry.  Usually, when going for a longer cable to deliver power, the wire needs to be thicker.  The longer the cable, the more voltage drop or power loss there is, so the power source has to push a larger amount down the wire to ensure the fridge will still run.
You may be able to find a solution from somewhere like Jaycar, or have someone make up a cable for you, but in my honest opinion the better option alround would be to head to an auto electrician and get a 12v outlet put in your boot.
Alot of people can do it themselves because it's relatively straightforward, but if its not your skill set it'd be a quick and easy job for an auto elect - shouldn't set you back too much at all & will give you alot of flexibility moving forward.

Hi Jules,

This particular fridge is a 12/24v only model, but you can run it from 240v using an adapter which we don't carry.
You can, however, pick one up from Bushmans directly - here.

G'day Sam,

We haven't done a sound test on these smaller capacity fridges, but I'd hazard a guess the Dometic would be the winner here.
They're known within the 12v fridge community to be the quietest option, and as a bit of a guide, we have done a sound test on the larger models which you can see here

G'day Andrew,

I've just checked and our Bushman Roadie 15L definitely doesn't come with a cover. We weren't aware they were doing a cover in their deal so we'll get in touch with them and see if that's something they can also offer to us. As far as we know there is no need to modify anything unless you wanted to run it below -18'C, in which case any modifications would be made at your own risk, and would void your warranty.

G'dau Ahuf,

The Bushman Roadie 15L Fridge Freezer has a powder-coated steel outer so it might warm up a little when it's alone in the car, but we've never heard a report of it being so hot that you'll be scalded by it.