i have a suburban a jetta and a chevy with 18" 16" and 15" respectively with all season tires and wheels. Is there anyway I can place the wheels and tires of one of these cars onto the 8 for snow driving. Has anyone done this before

 

Most likely not. the RX8 has a 5-114mm bolt circle. most VW jetta's have either 4-100 or 5-100mm bolt circles and chevy Pickups have 6-139mm bolt circle. and this doesn't include the brake fitment differences.