Starting price: $23,720 You don't go shopping for a Porsche Boxter and come home with a Miata, but the Porsche's label is about about all that's separating these two vehicles. The two cars have similar acceleration (zero to 60 in 6.5 seconds for the Porsche, seven seconds for the Miata), similar ratings from Consumer Reports (90 for Porsche, 89 for Mazda) and similar customer satisfaction. The Miata's available hardtop that kicks the starting price up above $27,000 only closes the gap further. What the Porsche does have that the Miata doesn't is engine, cooling, electrical system, power equipment and significant brake problems that add up to a lot of future costs over the life of the car. Boxter owners pay twice as much for that privilege, but at least they're getting a bit more trunk space out of the deal.