All of the rapid-prototyping I did at Uni was using a photosensitive resin that hardened once the laser beam had hit the CAD mapped out co-ordinates. The white end-plated wing at Barcelona looked very similar to the items I had a hand in designing. The end result was always a very resilient white (note similarities) polymer that was unbelievably accurate. My lecturer said that although the end product is fine for certain parts like wing-tips (he was more of an aviation fan than racing!) it couldn't really stand up to any great structural load. This makes me think that Ti may not have been the material used for an RP'd endplate - seems a bit strength/cost excessive!
[youtube]http://www.youtube.com/watch?v=_kEWSrbhHuI[/youtube]