Certain plants can be used to stun or kill fish in a pond, tidal pool or slow moving stream. I won't list them here because it isn't legal to use them. In a real survival situation, game and fish laws would be moot. You can find lists of the plants and how to gather, prepare and use them but, since it really takes no practice, save theknowledge for when it is needed.
FIsh weirs and traps are also effective even in moving water and, properly made and placed, can provide enough fish to feed a small group of people. Fish and game laws also apply with them so check local regs before you use them.
I've not tried it with a new-fangled car, but fish are very succeptable to electrical shock such as from an old fashioned car engine coil and battery. Likewise this is almost universally illegal in public waters.
Normal fishing methods are not ineffective and, particularly with multiple rigs, can produce a large amount of fish without having to be constantly tended. Such methods are jug (float) fishing where a line is suspended from a free-floating jug, limb lines where individual lines are attached to tree limbs overhanging the water, and trotlines, a long single line attached to an anchor on one end, a tree limb or root on the other with multiple baited drop lines along it's length. As before, local regs vary, but practice with construction and various baits helps.