Where to mount solar panels on roof?

My 2 100 watt panels got used as portable the first time I took them out and like the guys in the know say it’s not worth the hassle of storing them in the trailer, stringing out 40 foot of cord then drying them off before putting them away on a wet day. I’m going with the theory of figure out how much you need then add an extra panel and don’t worry about it as the extra panel will help make up for shaded panels. I do see the benefit of portable so I might make up a folding suitcase portable out of 2 50 watt panels so it’s a little easier to deal with but not 2 100 watt panels. There’s no way I’m going to spend the $ on a portable set up when I can get panels for half the price and make my own.