This is certainly a fight reserved for another topic, but I think you are missing the point here M5Power. The cars you mention are for the most part exotic models, so obviously they aren't going to have HUGE sales figures like that of your everyday Vectra or MX-5. Giles Guthrie was joking a bit (tounge-in-cheek, I know), but I think most folks would agree that the Avantime was a collassal flop for Renault given the success that it should have had.
Crazy styling doesn't win the public over in most circumstances, even with superior build quality and far superior technology as the latest versions of the Nissan Quest have proven. The early 3rd-Gen models (2004-2006) were pretty ugly on the outside and inside, hence the revamp for the 2007 model year. Early sales were pretty slow on the Quest, and they have stayed that way much to the surprise to the folks at Nissan.