With 26% of online automotive consumers intending to buy a used car, and another 32% unsure whether they'll buy new or used, undecided and used car shoppers comprise the majority of the online automotive population, according to a report from Jupiter Research.

The study says broadening online demographics will drive growth in Internet-generated used car sales from $28 billion in 2002 to $65 billion in 2007.

To capture share of this market, automotive sites must offer research tools and services better suited to used-car buyers. That includes price-oriented navigation, lemon checks, and warranties, according to Jupiter.