Don't kid yourself: that incident at your car was a line crossed. It time to play hardball now. Don't engage this guy at all. He'll freak for a short while, stay alert, its like pulling someone off a drug cold-turkey. The first month will be the worst but once he knows you aren't biting and have resources, he will leave you alone.
Don't be alone anywhere late for a while. It you must, be with friends and avoid the usual places (like the bar where he squeezed your knee). Protect yourself.