Shop the BMW Z4 against:

AUDI TT ROADSTER Front- or all-wheel-drive models available. Engines of 180, 225, and 250 horsepower. Priced from the mid-30s to nearly $50,000. New design for 2007 will feature the big nose-hugging grille that is becoming an Audi trademark.

FORD MUSTANG CONVERTIBLE Softer than the coupe, part of a combo among the best buys on the performance sports car market. It has 300 horsepower, great retro interior touches, leather seats, and you can squeeze two people into the small rear buckets. All for under $35,000.

LOTUS ELISE More expensive, in the mid-40s to more than $50,000, but this car has a removable hardtop, and a 190-horse engine that feels like 350 horsepower.

MERCEDES-BENZ SLK-CLASS You'll have to bottom feed in the SLK line if you want to remain even close in this price range (they start at about $45,000). But you'll still get a hardtop convertible with a standard 228-horse engine. This is the first true sports car Mercedes has built in quite some time.