This is a guide to painting ork vehicles, in the quick way, without sacrificing detail. Unfortuneatly my cameras pics can't be hosted by Image Shack so sorry no pics.
Mechrite Red ( a must if you don't want to paint 6-8 layers of red, 1 layer of this a red usually goes down flat ). Unfortuneatly I don't know any other campany that makes foundation paints, so your stuck with GW.
Blood Red / equivilant ( basicly a flat red )
Tin Bitz ( or dark bronze color )
Silver Metallic Paint ( can be any shade, depending on what you want, I usually go with Boltgun / Dark silver, because it looks more old and orky, but mithril silver can look good too. Alternativly, you can get a light bronze and or the silver )
Your Ork skin colors ( Now I don't know how you paint yours. I paint with dark angels basecoat, snot highlights, and goblin final highlights, reltively simpe )
Brown ( Any kind, I perferably paint with bestail, but 'your' shade is best )
Chestnut Ink ( or any brown ink )
Yellow ( bad Moon or equivalent )
Painting a WarBuggy
Start by painting all tin bitz. This is the undercarrage, gun mount, back engine/raidiator, speed freak sybol on pole, the steering wheel, insides of the wheel, and details on drivers. Don't mind if you get any on anything else, the more the better.
Now drybrush the entier tin bitz area with Boltgun Metal. If you have a lighter bronze, drybrush it on before the boltgun.
Paint all areas you want with mechrite red. It ok if it's not completely flat, just generally covering. I painted this on the drivers shirts, front of the buggy ( the 'sheild' ), the 'sheilds' on the wheels, and the bad moon face on the pole. You don't have to water down, just make sure it's not goopy.
The next step is the brown. Paint the straps and gloves and naturally leather stuff brown. You can alternate between colors for a more un-uniformy look. If you have chestnest ink use it on the brown for shading. You may want to fix the areas brown got on the red or silver.
Next, paint all mechrite red sufaces red. One coat should do, but if you want then do more then one. Make sure to water down. On the speedfreak symbol highlight with red, and leave some mechrite in the cracks.
Now the skin. This is on the drivers. Fairly self explanatory. Use you method. If you don't have one, then do this:
Basecoat: Dark Angels Green, Highlight: Snot Green, Final Highlight: Goblin Green
Now paint your details. If you want, add jags on the wheel gaurds and frontplate with your blue/yellow. You may want to use foundation paints. Also, if you want, make the ork jaw symbol or another glyph in black on the front plate.
Well, their you have it, easy ork buggy. Use this method on any ork vehicle and you got yourself a 2 hour vehicle!