Car Rentals business. Business Overview The car rental industry is extremely competitive, but think about a niche market that the big automotive rental companies are not servicing. Here are a few suggestions: *. Exclusively rent exotic sports cars like Porsches, BMWs, and Corvettes. *. Rent only motorcycles like Harley Davidson or Honda. *. Specialize in convertible cars for rent or perhaps sport utility vehicles. *. For environmentalists seeking car rentals,...