A D90 soft top is one of the coolest cars I've seen. Look to be hewn from a solid piece of metal. IIRC, back in 2000 a good condition D90 was about $25K - now they are going for more than $30+K. Certainly my Carrera did not increase in value.
There are a few D90 websites, they seem to have more than their fair share of mechanical issues however.
www.d-90.com/forum
forum.roversclub.org/forum/