We finally found one. After nine months of searching, DCist spied someone wearing a WMATA metrorail shirt this weekend on a Connecticut Avenue sidewalk. (It was a Metro Center shirt, like the the one at left). Since we love to talk about transit issues, DCist has a few thoughts on D.C.’s attempts to enter the world of transit chic. London promotes “Mind the Gap.” Paris glorifies its Art Nouveau Metropolitan signage. And New York has…