if your comparing a subaru to any inline 4 cylinder, yes it is very difficult to do a compression test. remove the intake, remove the battery, squeez your hands down there in a tiny ass spot. the 07's really suck. the emissions pump is right in the way on the back right cylinder. it took me and a friend like 30 min. to get that one, trying to line it up with the plug. keep in mind it was an aftermarket coilpack, so it wasnt made out of rubber for flexablenesssssssss.