Better off just running the car on the electric pump full stop then.
This type of pump works very well on mini's
http://www.ebay.com.au/itm/Electric-Uni ... 0306637735There are plenty of different brands of that style pump out there. Most local auto stores stock them, and depending on the brand and which store you can probably expect to pay $50-$80 or you can go for the ebay deals etc.
They can be a bit noisy, so it's best to fit them on the rear subframe under the fuel tank. That way they are also gravity fed from the tank which is a bonus. Fairly simple to fit as well, just need to run a wire to the fuse box and mount the thing, either screw it straight on, or rubber mount it.
There have been a few threads about this before so if you can find them in a search you will probably find some photos of how people have fitted them etc.
I will say though, the fittings are 5/16" while the fuel tank and pipe from front to rear is 1/4". You can probably buy 1/4" fittings to suit the pump, but if you use new 1/4" fuel hose you can push it onto the larger fitting, just not that easily.