Taken the Roadster to Jersey a couple of times, on the Condor fast cat from Poole. Once, when the tie was out at St Helier, the exhaust grounded at the rear, no damage. But the car was fully loaded, with luggage and co-pilot...
Taking the Aero Plus 8 on the same service on 31st March so I'll find out if it is a problem. I doubt it.
Interestingly both times the load master commented that as the car had a fly off handbrake they would chock it as well as strap it down.