The driver's tan

In “The Lost Continent” Bill Bryson describes the “farmer’s tan” – a white torso, with very brown face and forearms. It’s OK while fully dressed, but a bit odd when you have your shirt off. After my 5-hour drive from Kigali, I realised that I am developing the African driver’s tan – similar to the farmer’s except that the left arm, which is beside the open window, is darker than the right. Oops!