Depending on the type of plastic some can be glued and some can't. For instance MEK will attack polyethylene, but will run off of ABS. For a quick fix I suggest some of Gorilla's black tape made like Duct tape. Last summer the upper radiator hose on my 91 Dakota developed a split of about an inch on the top just past the radiator hose connector. A friend had some of the tape and after wiping the hose off as best I could I wrapped a couple of laps over the split, filled it with water and and drove it some 5 miles home and it didn't leak a drop. It's really good stuff IMHO.