My assumption would be that if it was hollow, then it may allow more flex, and an aftermarket one from say addco would be a good upgrade. I have heard that our stock fronts are good, but the rears could be upgraded and it does help. One of the things I am trying to do with my car is make it one of the most "complete" mx6s out there with 90% of all all popular performace mods, while maintaining a stock look.