I'd look for a Skoda Superb. It hasn't got a premium badge but I think you'd be impressed by its upmarket cabin. Your budget will get you a 2016 or 2017 example and it has a huge boot. Depending on how many miles you cover, you might find a petrol more suitable than a diesel. If you don't cover many motorway miles a year, resist the temptation of a diesel as it might prove troublesome further down the line. Also consider a Skoda Octavia if you'd like something smaller.