Do XTC baffles work?

I just installed some 3 1/2" speakers in the fairing of my motorocycle.  Essentially they sit out in the open and have no enclosure behind them.  They sound best when I equalize the sub-lows and lows down to minimal levels. I know they're only 3.5" speakers but I'd like to try to get some more volume and possibly more bass out of them.  (With the bass at high levels, they clip like crazy.)

I'm considering getting some of the XTC foam baffles from Crutchfield. (Supposedly you can smush them into tight spaces which is what I have.)

I'll probably get them anyhow for water protection but am interested in opinions as to whether this will help me get some more volume and/or bass.  Thanks.

Yeah, I was thinking that about foam. Althoufh I did read some posts here and elsehwere about people who had cut slits or holes in the back of the foam baffles to let let the cone breathe or something like that.. 

I was also considering building my own enclosures out of a more rigid material such as 4" PVC.  That way I can get them to fit in my limited space.  Should I cut holes in these and then put some mesh and polyfill over the holes I make?

But hey, I'm not a pro, just trying to get the most out of 3.5 speakers since I don't think I can get 6x9's and a sub on a motorcycle. I don't expect the world from them but would like to optimize as much as possible for that size speaker.