We were blessed by our Sales guy... he fought for us and got us the winter mats included.

Options we've bought/acquired from "hand-me-downs":

• trunk-area carpet liner (the velcro-backed carpeted style one)
• cargo blocks (these: https://www.amazon.com/Multipurpose-Cargo-Organizer-Storage-Available/dp/B06VVPWSXM) You could use them with the OEM carpeted trunk, but over-time it causes wear and "tufting"... so having a liner is ideal).
• A collapsible trunk organizer (https://www.leevalley.com/en-ca/shop/home/automotive/trunk-organizers/67069-trunk-organizers) - great for storing... "stuff" (our AMA winter kit, shopping bags, micro-fibre rags, spray bottles, etc), held into a corner of the trunk with one cargo block. Regardless of how... spirited... I drive, it cannot move/shift.
• Wheel Woolies Superior Boar's Hair Snow Brush (super soft, and cannot scratch the paint, but long enough handle to clear the roof fully).
• a brass-bladed ice scraper
• Thinkware F800Pro dual-channel dashcam (salvage yard was kind enough to remove it from my wife's written-off BMW X1 so we kept it for the I5)

Bought specifically for the I5:

• 3-pak of 6-inch "credit card" style squeegees (and a spray-bottle of washer fluid) to clean of the rear window)
• small spray-bottle filled with "interior cleaner" to de-fingerprint the screens while parked... :D
• 2-pak upgraded USB-C for the center console (https://www.amazon.ca/gp/product/B096ZKFXNH) - super easy upgrade, and can charge 4 devices at once now... instead of 2.
• 12V BT battery monitoring - after a one-time issue (while the car was being wrapped with PPF, they drained the 12V and we had to jump it) - never had a problem since... :P
• ODBLink for data logging (I think it was the ODBLink MX+ ...? The one recommended by ABRP).
• 2-pak of USB LED... probably from AliExpress as I can't find the order #... stuck them in the rear USB slots for a bit of ambient lighting.