While at a junkyard a couple days ago, I pulled a pair of gas struts from an M Class Mercedes. Not sure if they will work on my son's Crossfire Coupe trunk lid. My son lives 7 hours away. The cylinder part is 13 inches long and the extended length is 25 inches. They are oem and really hard to compress. The M Class rear hatch was really heavy and these held it up no problem. So will they work and what length should they be?