Check out the news page for some pics of the A610 prototype featured in the current issue of Mille Miles.
Based on the USA GTA this car (built in 1989) looks fairly similar to the finished product. Notice the indicators painted body colour and later removed as a result of a redesigned nose and front wings.
Unfortunately this car is still blessed with the orginal GTA interior but otherwise has full A610 running gear including the 3.0 litre Z7X engine along with a few additions that were dropped from the production car including:
Genuine BBS wheels 15" front 16" rear
Electronic adjustable damping (very rare GTA option)
There was no ABS fitted to this prototype although it was available as an option on late GTA's (for around £2000!)
The USA GTA and A610 are close cousins. The A610's revised (stronger) front chassis is a result of more stringent requirements in the USA. The A610 under bonnet layout (front) also comes straight from the USA GTA.