This is an excellent example of product cannibalization. An A4 Cabrio is rumored to replace both the TT Roadster and A5 Cabriolet. Based on the A3, the A4 Cab will ride on the automaker’s MQB architecture with a transverse layout. The new convertible could be immensely more affordable than the two models it's replacing– possibly to the tune of more than $10,000. Sales for both the TT and A5 have declined consistently since 2011.