Although I do mostly gravel or dirt road driving with my 570 Touring, there is the odd time I head off into the bush where clearance can be an issue.

What is the benefit of Aluminum bottom plates VS Plastic plates?
I’m assuming the plastic variation are quite hard so whats the real difference?

I’m fairly handy so am curious if these can be mounted in the garage (by me) or does it have to be a service person?