Making a late dash for TG's coveted Kraziest Koncept title comes the C-Cactus, the highlight of the green side of Citroen's Frankfurt stand.
Based on the C4 platform, the C-Cactus is a diesel-electric hybrid which combines a 70bhp HDi engine with a 30bhp electric motor. That means a combined cycle of 83mpg and just 78g/km of CO2.
But that's where the C-Cactus leaves traditional green behind and veers of into properly daft territory. The unique looks are the product of a streamlined design process - Citroen engineers say they 'removed all parts that were non-essential to the running of the car' in the name of a cheaper production process.
That means the cabin is made up of just 200 parts - half the usual number - and dispenses with a dashboard in favour of an expanded centre console and steering wheel functions.
There's no window winders - just sliding glass panels - while the front bumper is made of the same part as the lower tailgate.
Citroen says such simplification means that the C-Cactus could be offered for the same price as a similarly sized non-hybrid car, negating the increased cost of hybrid technology.
What with it being a Green Concept, there's plenty of recycling going on: recycled leather, recycled tyres, recycled glass. Those tyres are narrower to lower rolling resistance, but there's still room under the 'arches for an impressive set of 21-inch alloys.
If that all sounds a bit sensible, you'll be glad to know that - in genuine high-concept style - the C-Cactus' ignition key is an MP3 player with a touch screen. All non-essential parts indeed...
Citroen also unveiled a slightly less radical concept alongside the C-Cactus: the Airscape concept, which previews the styling of the next-generation C5.
Strip away the folding-carbon roof and V6 hybrid engine here and it's a good pointer as to what Citroen's next family car will look like.
A stronger swage line and high-mounted, wraparound light clusters should remain - as will the dual bonnet creases - but aside from that we can expect reasonably conservative styling in the next C5. Here's hoping it turns out a bit more exciting than the Laguna.