When working on these cars is it really necessary to put the car in maintenance mode?
What kinda gremlins problems would arise if this procedure wasn't followed if any at all.

 

depends on the task in hand. if you can fit your hands, let's say to do the oil filter housing gasket, then so be it. I found myself removing the whole nose to do major work. at times only the top rail to do an alternator replacement. So, it really depends.