Gmod racer crash

Recently me and a friend went through the old gmod racer gamemode and fixed it up/updated it. We got through a good chunk of errors to the point where all the menus work, scoreboards etc but we just have one huge issue. When you queue for a race and the race starts gmod just straight up crashes. The crash log http://dumps.metastruct.uk.to/dumper.py?dump=exec_klggmr_1678491_crash_2015_8_3T11_15_51C0.mdmp
Any help is appreciated