My brother did it with his RA28, and it worked great.
Just make yourself some new brackets and bolt them on, make yourself some new bushings to mount the second one to the suspension arm bolt thingy, and cut a bigger hole in the chassis to fit them both through.
It was really easy, it cost all of about thirty bucks (using left over urethane chunks we scored from a urethane technicians big) and it makes a huge difference to the handling.
We just used 3mm steel flat bar tofor brackets (just bent and drilled) with some 12mm urethane spacers between the two bars and between the bars and the bracketry bits.