Bertberr : many thread talk about that, but for you :
Mad Rat hasnt bearing ball, a painted shell and wing, plastic shocks and plastic part (the xpro has plastic/graphit part)
The part really needed for the Mad Rat are the bearing ball set and some other aloy shocks, who are really cheap if you know where to buy it
TQ Racing is the distributor for the US market. Ansmann for the european market. Team C Racing is the builder and the distributor for the asian market.
If you want more information and some picture of a Mad Rat, check my blog (in french)