Where can I buy a [component]?

Including:

or any other parts/modification

There are obviously many choices for sources.  Local shops often have common items such as plugs, wires and fluids.  Don't forget specialty speed shops for more esoteric stuff, such as clutches and fuel pumps.  Other retail chains handle audio, cosmetics and accessories.  Non-automotive outlets, such as industrial supply stores and aviation equipment vendors, often have equipment which can easily be adapted for DSM use at a fraction of the cost.  For a good example, see Brad Baur's Westech EGT installation page, where he installs an EGT originally means for airplanes.

Several vendors specialize in equipment for DSM cars; many have comprehensive online catalogs.  Between them all, they offer just about every possible upgrade for both first and second-generation cars.  Look around!  Check the archives, too, as many people have posted good deals on various parts.

For those who are interested in used parts, be certain to check out the DSM Parts Trader and DSMtrader.com.  These classified ad databases specialize in DSMs only, and good deals are not hard to find.  Some vendors post their current specials there, too.