I was wandering what trailers there are available that open up into the full base. Not the whole MP-04 set though.
Other than the one that came with MP-04 Prime, and the Justitoys non-transformable trailer, the only other one released so far is made by a member here, dalianj, which is an exact oversized replica of the G1 trailer (unofficially but fittingly referred to as the 'dalianj trailer'), with a Roller and all other oversized G1 accessories as well. It had a small production run and last I saw on eBay last year, sells for $200+.
Before you do that, I encourage you to take the hands-on approach. You can get toy trucks for like $20 each. Make sure they're either in the 1:24 or 1:32 scale. Take the trailer, either keep or throw away the cab, and spray-paint it silver. Make a stencil and paint the blue stripe onto the side. With my particular truck, I used a 1:32 toy, which was slightly too small. This was fixed by adding some lifts so that the trailer sits higher, and it looked just fine on my Prime. It's cheap, it's (relatively) painless, and it looks pretty good. Alas, my stencils for the side-stripe weren't very good, so I messed up the paint job. I cut apart a Finding Nemo poster and glued it onto the side of the trailer to cover up my bad paint job. My MP Prime is now happily advertising Finding Nemo. A robot in disguise indeed.
i need a trailer that turns into the repair bay so, good idea, but no thanks. Also i was looking in the gallery of `TFW2005 in the MP section and there's a trailer that transforms and is the same box as the justitoys one just with out hte justitoys written on the box. it has roller and all that, but i can't find one anywhere. is it real?
IG-TF004A New Original Color Trailer For MP-01 - Transformers Masterpiece Masterpiece at BigBadToyStore there's a new one coming out that may be a cheaper alternative than an mp04 trailer of you don't mind it being unofficial