BMW and Audi are pretty sweet for 3 years, then all the parts start falling off as you leave your driveway. Fun to drive, much less reliable than Porsche.
With your need for longevity, price point, and soft top I'd say Lexus IS Convertible. Still fun to drive and dead nuts reliable, a decent back seat, and looks sorta BMWish if you take your glasses off.
My daughter had a 2014 IS hardtop and it was a great car.
Here is one:
https://www.carfax.com/vehicle/JTHFF2C25C2525984
Or an older SC430:
https://www.carfax.com/vehicle/JTHFN45Y399020526