I get an image in my head and tend to aim for that, making lists but then usually accompanied by a cup of tea and a chat on the phone it goes wildly out of controll. BMWs tend to stay simple where as the Opels go waaaaay overboard, like a 2.5 V6 Corsa has inspired a 5.2 V12 Corsa with a little encouragement from my fabrication expert mate.