Project: 2003 BMW M3

[Beej]

Yeah, that's basically what I settled on, though I haven't gotten around to the structural foam yet. I sleep well at night.

One argument for welding that you get to tie all the layers together a bit better, as opposed to just adding another layer to reduce flex. Essentially you drill from the bottom up to #4 in this picture and rosette weld all the layers together.


In the rear, you can fill up the cavity with foam, which essentially makes it solid. Apparently you can't in the front - the cavity is huge, you can't block passageways off as you can in the rear, and the fill point is not at the top.

I just think that with stockish power and reasonable treatment, it'll be a long time before they fail - longer than I'd trust a weld to not rust.

Btw, if you want to see trunk floor failure (start issue, lol), check out the last picture in this listing: <!-- m --><a class="postlink" href="https://washingtondc.craigslist.org/nva/cto/5260452379.html">https://washingtondc.craigslist.org/nva ... 52379.html</a><!-- m -->