dual use is a shortfall in TT's creativity and vision ... for $10 more, Magellan's car kit provides dual use - iPhone/Touch, works w/ skins/cases, bluetooth when not in base, and firmer notches to hold in landscape better
(observed, not personal experience since i own a TT car kit 😀 ...)
p.s. i wonder if there will be a market for an attachment that will make the TT car kit dual use ... hmm