Graham,
Different, I can advise you on. For example a Lotus Esprit in mustard yellow was my first thought. Being from Norfolk and a fan of the late Colin Chapman, I quite seriously want one before they are too old. The late ones are around £25,000. Like the NSX, it is a car enthusiast’s choice and people also recognise it.
But classy? Now you are pushing my skill set. Aston Martin has been voted the UK’s coolest brand but the Vantage is going to be out of reach for a little longer. A used DB7 with 40,000 miles on an R plate would be within your budget.
Apart from the Mercedes, which is a sensible choice, the car that sounds right for you is the Lexus SC 430 cabriolet. £30,000 will buy you a 10,000 – 20,000 mile car in any number of brave metallic colours. Pull up at a hotel with a doorman and I guarantee he will rush to take your luggage and park your car in the VIP spaces.