The PERT rally cars are Mitsubishi's, but they were sent for Homologation to run under the Proton badge.
adibk10,
And yes there is a whole stable of race and rally prepped cars in Proton and R3, but not all of them need sponsors... Maybe what your friend saw was just another car in Proton...
Don't assume something and think you know it all... You might think that you do, but you can be so very wrong... many other carmakers seek for sponsorship to run races, that doesn't make them cheap or is it wrong... Look at Ferrari, they got Bridgestone with them... Now why is that ??? Think about it...