Ok well here is my list of stuff I drag to races. Mind you most of these things have not broken but here goes...
Bearings (8x16x5 and 15x21x4) at least a couple of each, if one siezes you have a replacement
Hinge Pin Bushings (The one, two, three dot things, these wear, can help tighten up that suspension)
Hinge Pins (Outer and Inner)
Top Shock Bushings
Those little red and blue bushings
Shock Shafts (These have and do bend on good hits (remember not always your fault, sometimes that crazy knuckle head who hits you head on))
A-Arms (Front bottom and Tops, Rears)
Rear Hub carrier (used to break these on my T alot, none on buggy yet)
Clutch (Always have a spare complete clutch, bell and flywheel)
Camber Links (Any ball links really, they tend to be one of the first things to break in a hard impact (Not a bad thing
)
Spare screws/ nuts (All sizes, but most important, 3x12s, 3x14s, 4x12s, 4x14s, M3 locknuts, M3 Flanged for shocks, also the top shock screws and the motor mount ones with lock washers)
Diff Cases
Exhaust hanger ( also the set screws for it)
Spare Glow plugs
Spare Fuel Tubing
Spare Fuel Tank
Complete Air Filter Assembly (Also spare filter elements)
Wheel Nuts
Optional:
Dog Bones (F/R and Center) / Rebuild Kit (they get bent and worn)
Outdrives (F/R)
Turnbuckles
Anypart that you upgraded with something else
Servo (Something that can do double duty if needed)
Battery for reciever
I'm sure there are other things to add to this list. This is the minimum I would go with to a race. I have almost always had a part I have needed if something broke on my car, and in most cases even for other's RC8/ RC8T... I also in worst case, always can strip stuff on my RC8T chassis. Also most of the spares I have are parts that have been upgraded or when I buy parts, I buy them in 2's.