Things that the IWC has vs. "standard" Street Weapon:
Slotted graphite chassis
0- and 10-degree front bulkheads
Reversible 3-degree caster blocks
Graphite shock towers
Graphite suspension arms
Threaded shock bodies
Titanium nitride shock shafts
Ball bearing steering
Lowered motor plate
2.5-degree toe-in rear hubs
High-rate black springs
Ball bearing differentials
High-efficiency (blue) drive belts
Aluminum layshaft
Aluminum wheel nuts
Aluminum rear swing shafts
Lunsford titanium turnbuckles
Front and rear sway bars
Wide track wheels
Blue compound racing slicks
Machined rear bearing spacers
Machined aluminum thrust washers
Add the Cyrul kit to this car, and despite what most people say, this car can compete with many of the newer designs. Of course, by the time you spend all that money, you may as well get a newer design. But it's a great car to start with (I did) and it handles well.
The Cyrul kit, by the way, includes the following:
Two shortened threaded front shock bodies with threaded shock collars
Two shortened shock shafts (1-1/4" long)
One graphite front shock tower (RC7506)
One grahite rear shock tower (RC7507)
One graphite rear transmission brace (RC7508)
One aluminum front bulkhead (blue anodized) (RC7511)
One aluminum rear bulkhead (blue anodized) (RC7512)
Two aluminum rear standoffs (blue anodized) (RC7513)
One front sway bar (RC7514)
Two TC3 rear hub carriers (RC7516)
Two 1/8" x 1-3/16" rear hinge pins
Two 5-40 x 1/8" set screws
Thirteen 4-40 x 1/4" flat head screws (blue anodized, hex head)
One blue anodized counter sunk washer
One 1/16" diameter front sway bar
Here's mine: