The new 49ers stadium in Santa Clara hit a construction milestone Tuesday when the first seats were installed.The seats are bright and shiny and red. Miranda Margheim of Fremont and her son Stephen were the first fans to try them out. A new stadium is old hat for the Miranda. She has been a season ticket holder since 1971 when the 49ers played in Kezar Stadium."You dream of something like this, but to see it and witness it. Oh my God," Miranda Margheim said.Miranda said the Levi's Stadium seats beat Stanford, Candlestick and Kezar, noting that she won't get splinters in Santa Clara.The first section was 14 seats long, meaning the construction crew has just 68,484 more to go. The entire installation timeline to install them all is 17,000 man-hours. The seats were manufactured in Hayward by Plastikon. Plasitikon had to keep the contract a secret until now. Tyana Dominguez of Plastikon said she bought season tickets, adding it will be "awesome" to sit in a seat her company manufactured.Dominguez says she was able to hire 40 people just to build the seats.Plastikon's contract is just one of 35 awarded to small businesses that add up to $46 million, according to the...