MIne was welded in three places too. But they weren't very substantial welds. I took them for tack welds till something else more permanent was done,'
I installed two 7/16 th bolts to hold the aft bracket in place by coming in thru the depression in the cargo bay.
Forward bracket must be welded in place too, but its hard to see because of the mud flap and the foam. May need to get it on a hoist.
Here are pics of the finished job.
2011 Solera 235S