Don't know about a pattern but the link below has a semi fabric in the lower left hand corner. Good luck!
http://search.myquiltshops.com/cgi-s...myqssearch.cgi
Whoops, that didn't work. Go to quiltshops.com and type in Trucks in the search box. You'll have to sift thru all the pages but it was there!!
Ok, found it at Fabric shack.com
http://www.fabricshack.com/cgi-bin/S...alexhenry7209b
Can you use this and scale however large you want it?
http://allaboutdinosaurs.com/paint/vehicles/semi.shtml