Other than a bike rack type of securing strap, (a roof rack strap with a wide hook on on end) it’s not happening. The straps will also resonanate like crazy. I thought about this before and I think a tow hitch with a luggage rack like you see on some mini vans is your only option for secure luggage space, the lotus has a ski rack that may work for locations but I doubt even with padding this type of rack will leave no damage.
Personally, I probably would avoid putting anything on the boot lid unless you have a spare boot lid!
The problem with composities is that it's really hard to determine when damage has been done, any strain which is disproportionate the to the direction of the weave risks cracking or delamination; neither which is good...
Holes definitely very bad, but straps also unless they are precisely distributed risk strain being placed unevenly over the surface of the structure, excess strain on one side vs. too little on the other, and either a) the rack moves, or b) the lid moves, again undesirable.
I think that loading like is ultimately not for the Roadster, if you do try it then start with lots of padding, or maybe even better a soft bag which you strap to the lid directly, the metal rack adds mass and strain, a soft bag will mitigate some of that. My two cents of course.
I spoke with Anthony from revo today and he's certain it will work. I have no intention of driving fast with this as I'll mainly use it for touring. That said, here are some videos which highlight the strength of the grip via the suction cups with no metal or straps contacting the paint:
Update after enquiring about the swivel joints seen in the Elise pic:
I think the standard rack will fit as the Tesla has a flatter boot lid, than the Elise. If it does not work I can post you some, the rack is much much more secure with the standard rack and with these swivel joints can only carry 15kg.
I will post you some grommets separately as the rack will be despatched from our e commerce partner.
Please do let me know how you get on.