When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Most track day or HPDE events will require a roll bar for a convertible. I would expect that you might have to have one made but who knows, there may be bars available. Try doing a Google "search on Corvette convertible roll bars". C4 roll bars are usually attached to the frame. Small parts of the rear cargo deck will have to be cut open to get to the frame rails. Not a big cut, but something like 4"x6" or so. Plates will be welded to the frame and the bar can be either bolted in or welded in.
At a minimum, I would suggest a 4-point bar that also has a harness bar as part of the unit so that you can use a 5-point harness. The top part of the roll bar should extend at least 2" inches above your head while wearing a helmet.