Any contaminatione will compromise the strength of the bond in a long crack repair. . If there is any delamination crack repair is not advised. A fresh crack can often be repaired but every crack is like a snow flake. No two are the same. The same holds true for the technical ability of the repair person doing the repair (no two repair technicians are the same.). Even a perfectly filled crack will still be slitely noticeable from the inside looking out. At certain angles the sun will kind of lite it up. Long crack repair is worth a try on an expensive piece of glass. Honestly the glass for that truck should be hade for under $100 and they are pretty easy to rope in yourself.