After hearing of things falling down the vents under the front seats I got some Clip on covers. No idea if it's really necessary but stuff rattling away with no way if getting it out would bother me so I bought some off Amazon. Pretty cheap (others may better or cheaper but nowhere had them in stock when I ordered so I got these:
https://amzn.eu/d/dBzccSl
I didn't get new carpets/mats but after a year I've worn a hole through the driver's mat which I've never done before!!
Agree on the trays for central console. It's just too big and deep for small items.
We also bought some rubberised covers that go over the seatbelt clips to stop rattles. Not strictly necessary but Mrs. McChimp found the rattles infuriating (I usually have music on too loud to notice!!)