Very well described, thanks.
Recently I've been driving a FWD car that was designed with a lot of negative castor (same as we are talking about) to help compensate for the natural effects of FWD steering. It is a American car (hate it already) that my parents bought. When I take my 99 Y.O. mother to doctor appoints it is the only vehicle that she can get in and out of easily, so that's what we use. I do not like it at all. It behaves exactly like Ulix described. Not only is it no fun to drive, it can even be dangerous if you aren't paying 100% attention all of the time. As it easily wants to wonder into the next lane quickly. Unfortunately there is no castor adjustment on that vehicle.