Ferrari 612 Scaglietti - 4 door Fezzas are depreciation specials. Think 456, 400. If you can afford the maintenance it'll be the cheapest way to show off the Ferrari Owners Club card.
www.cars.com 120k Ferrari 612's
Mercedes CL - The bigger the engine the bigger the price drop. Go with the CL65 AMG. If you're lucky, you'll get all the once very expensive gismos for free: Night vision, Active Cruise Control, Massage Seats, etc...
Porsche Cayenne - Pick the Turbo for maximum bargain and minimum fuel efficiency. The Turbo (S) will also just prove fast enough to outrun the ugly.
Porsche Boxter S - The early ones. So much cheap fun you'll forget you're in a Boxter. They handle like they're on rails, and they cost half the price of a new Miata. Heck you'll even forget your local hairdresser has one.
Jaguar XJR - An all aluminum supercharged saloon for under 20k, what's not to love? Sure the bi-annual air pump and drivetrain belt replacements will have you remortgaging your house, but those are worries for later. www.cars.com New XJR's for under 20k
Chevrolet Corvette - So cheap you'll take the embarrassment of owning one in stride as you lay down parking lines at every traffic light in town. For the full effect choose on in fluo green or bright yellow. ZO6 minimum.
BMW 7 Series - A three year old 7-Series for the price of a new 1-Series? Yes please. Just know that every electronic gizmo will go wrong and your local mechanic won't have the tools or know-how to fix them.
BMW Z4M - Bangle design rear wheel drive with an M badge for under 30k. This mid-life cricis special is guaranteed to have you reminisce pre-marital times picking up girls in your IROC Z28.
996 Porsche Turbo - Alexotic's favorite. Rock solid engine and won't depreciate much further below the 40k mark. Oh and honey, don't worry it's a 4 wheel drive.
Honorable Mention: Bentley Arnage, Maybach 57/ 62, Mercedes CLK63 AMG Black Series, Lotus Elise/ Exige
For added effect, buy one in the states, with lots of kilometers. If a seamlessly stamped service record book is missing, be sure to splurge on additional endless warranties. If you play the game right, and fall in love with a depreciation special, you'll be able to live 5 years in the past, and enjoy a 'new' sports car for a fraction of the price every half decade. Look for the Porsche Panamera and the Ferrari FF to be 2016's depreciation specials. I suggest you keep yourself entertained with a 612 Scaglietti and a Jaguar XJR for the time being. Or any other of the above shown sports cars for that matter.