Big truck salvages can let you get replacement parts for your semi cheaply. Most will salvage the engine, transmission, gears, drive shafts and wheels and tires. You can get salvaged interior parts like seat, carpet, steering wheels or even the windows. Many salvage yards will allow you to walk around and see just what you didn't know you needed. You can get lights and light covers, and even
. ashtrays from the salvage yards. You can check one out at http://www.bigtrucksalvage.com/(S(mwefoi45nmlf3jb2zeo0lifd))/index.aspx.