ebuggy Trailer Concept Allows Electric Cars to Travel Any Distance

This seems like an interesting piece of transitional tech. It's not an 'ideal world' solution but until the science of battery storage goes through some step-changes (probably not that far off; superconductors, nano-tech, man-made materials, Moore's Law, blah blah) this could be a practical way to deal with the issue of long-distance travel for electric vehicles.

A Stuttgart-based startup, ebuggy.com, has finished working on its prototype battery trailer which could give electric cars unrestricted mobility on motorways, with no range limitations. The plan is to build a network of ebuggy relay stations at which drivers of electric cars can hitch up battery trailers.

If required, an ebuggy battery trailer can be hitched up at an ebuggy relay station and the journey continued using the energy from the ebuggy. On arrival in the destination area, the ebuggy is dropped off again at the final service station. ebuggy can be exchanged whenever necessary during longer journeys so that unlimited ranges can be achieved. And all this within two minutes.

The ebuggy prototype was constructed with the support of Germany's Ministry of Economics and Technology (BMWi) and project partners such as the Fraunhofer Institut IPA and Stuttgart University.

The two obvious, but probably minor, drawbacks I see are:

1. Whatever the performance of the car, it is always going to be curtailed by the speed restrictions on towing a trailer (which is probably pretty heavy too), which will be frustrating on a motorway.
2. You'd always have to carry a spare registration plate to go on the trailer, which on multiple swop journey's will run the risk of leaving it behind. Maybe by the time this system arrived, car manufacturers will have established a standard protocol for transmitting a registration id to a digital licence plate display for any trailer via the standard lights hook-up?

What do you think?