they specifially say in the cams manual they are eligible for PRC.
the main problem isnt weight. theres alot of fat that can be cut out of them, and from the factory they are similar in diamensions and weight to the last gen WRX. weight distribution is similar too.
the suspension is a bit of a hassle, but if your going to the trouble of building a rally car, the suspension should be FAR from stock, and will be altered to suit.
the main problem atm, is the restrictor rule, which is most advantagous to cars around 2L capacity. there has been rumours floating that cams may revise this rule. im doubtful tbh.
hopefully if i can convince the ball and chain, ill be having a go on dirt and see how a GTR compares to the wrx/evo boys.