First of all, did you do a Bonneville Club search for "toluene"? There is a lot of helpful info available before you determine to try using it.
Having said that, toluene can be a great gas additive. As far as I know, adding it to MTBE or Ethanol-blended gas won't hurt anything, because octane is octane. It will all burn. However, you may want to get an experienced opinion on that matter, just to verify my comments.
Bottom line: if you do your homework and keep track of the octane level every time you add toluene, you should be able to run it with great success.
1997 SE w/SLE package
"White curse? I think it'* more like.... WHITE FURY!" - MyLittleBlackBird