The biggest challenge with making your own wrap protectors is making the compound curve to match the trailer, plus the much tighter curve for the lower part to protect the front banana wraps. I have seen protectors made out of black Plexiglas I believe, so it can be done.
Pretty much, it all depends on how much money you want to spend, how much work you want to put into it, and what look you want. Many folks don't bother with the wrap protectors at all. We decided to put them on because we like the look, and they cover a pretty big ding on one of the front panels.