But Meghan isn't the only royal who's closed her own door before - as many pointed out on Twitter, her sister-in-law, Kate Middleton, has actually done it on several occasions.
Others were quick to point out that Meghan has only been a royal for four months - she's likely to still be in the habit of shutting her own doors.
The Duchess of Sussex stepped out for her first solo event this week since becoming a member of the royal family.
The royal beauty attended the opening of the new Oceania art exhibit where she viewed and met with various artists from New Zealand, Fiji, the Kingdom of Tonga and Australia - the countries she and Prince Harry will be visiting in October.
"Current state: Poking my own eyes out after reading Meghan "broke protocol" by shutting her vehicle door".
"Meghan Markle leaves people in shock as she shuts own CAR DOOR on first solo engagement", the Express reported.
Whether her security is quicker to shut the door for her after this remains to be seen.
William Hanson, an etiquette and protocol coach, tweeted that the door close was not a protocol breach.
Despite the hoopla, the newly minted royal has closed her own door before.
Meghan has also had to delete all her social media accounts and her lifestyle blog, and won't be able to venture out in public alone anymore.
Last week, in her first solo initiative as a royal, the duchess lent her support to the launch of a charity cookbook aimed at helping a community project formed following London's Grenfell Tower fire disaster past year in which 71 people died.