In the US, there's a regulation mandating the size of the lit area for the turn signal exceed a certain surface area. The European style amber signal area on mo

In the US, there's a regulation mandating the size of the lit area for the turn signal exceed a certain surface area. The European style amber signal area on most standard-sized or small cars is unlikely to comply. This (and regulations around the amount of red reflector in taillights) is the reason why most Americanized cars get terrible taillights with reused brake lights.