I use a few of the Mugen Titanim screws from the MBX6 upper screw set on my car but they are in very low-stress areas that don't generally see dirt. I only used them for looks up top. Never use them when the screw is threading into aluminum or steel (basically places that you need to use loctite). They WILL strip when trying to remove them here. I also wouldn't recommend using them in high stress areas or places that get pounded (like under the chassis). At a good $1 or more a piece it just isn't worth the weight savings.
Today you can save a TON of more weight in other places. The newer truggy tires are super light. Titanium turnbuckles, aluminum drive line parts (although on the truggy's I would not recommend running the aluminum axles), aluminum steering posts, LiPo receiver packs, lightened cooling heads, lighter exhaust systems, and most importantly the body. I can't tell you much money peeps spend on lightening up their car yet they paint, back and decal up their bodies to weigh a good 3-4 oz's heavier than they should.....LOL
