Whichever you go for, if there is a concern about vulnerability then get whoever makes it to simply weld on an extra skin of metal to the bottom section to protect from stones and the like. Mulfab did this for me although Peter said he had never had a problem.
My valance helps protect my SiFab radiator
![[Linked Image]](https://www.tm-img.com/images/2019/11/18/8238BE2F-2239-4DB3-868B-2997D06286EB.jpg)