i've been asked to do a car cake for a birthday boy to feed 10 people, can someone tell me what size shall i do it? also does anyone have any tips on how to ice a cake like that that has different colors in buttercream?i want to do a cake similar to this picture.

If you look in my photos, the train 1st birthday cake is all buttercream. I used a very small plastic palette knife and applied the detailed bc with that. Then I smoothed as normal and then outlined it. As far as the servings, I think you could use the wilton loaf pan and just do the half size. I used this for my dump truck cake in my photos. I think I figured it up to serve 8 but you could make it a little bigger. I just used half of the pan. Good luck!

If you look in my photos, the train 1st birthday cake is all buttercream. I used a very small plastic palette knife and applied the detailed bc with that. Then I smoothed as normal and then outlined it. As far as the servings, I think you could use the wilton loaf pan and just do the half size. I used this for my dump truck cake in my photos. I think I figured it up to serve 8 but you could make it a little bigger. I just used half of the pan. Good luck!

The car in my photos was also all buttercream. I have a recipes that crusts pretty well, so I just gave each layer a chance to rest before smoothing and then adding the next layer.

can comeone tell me what cake pans to use to get a car cake for 10 people? i'm also thinking of piping small stars to cover the cake. does anyone have any tips on how to assemble the cake?

Here's some pictorials on building a cake very similar to the one pictured above.
http://www.andreasrecipes.com/2007/12/07/lightening-mcqueen-birthday-cake/
http://5150life.blogspot.com/2008/02/mondays-munchies.html
I make them very similarly, using a 9x13.