Flights with ryanair to K'ruhe. Warning: 80 quid for bikes. 5 quid each way fee. Return train to Stansted (or wherevere you will fly to). The airport you land in (Karlsruhe-Baden) is not in Karlsruhe, but Baden-Baden, so you'll need to get a train/taxi from there. It adds up.
Flights with ryanair to K'ruhe. Warning: 80 quid for bikes. 5 quid each way fee. Return train to Stansted (or wherevere you will fly to). The airport you land in (Karlsruhe-Baden) is not in Karlsruhe, but Baden-Baden, so you'll need to get a train/taxi from there. It adds up.