There's a few GT3's and such out there with little trailer hitches for a small tire carrier. It can be done, hell I even saw a C6 Z06 with a trailer hitch that would tow a skidoo (you can google it, he was in rochester NY). Theres a company who makes them for earlier boxsters and 996's, ill attach a link to their site. Its not for a 997 but maybe it can lead you in the right direction
https://porschehitch.com/product
*edit:
Found another company after a quick google search
https://www.sporttows.com/product-page/class-1-receiver-for-porsche