Thanks to all in this forum for the spare tire info. Ordered from the Miami eBay seller ($39.90 + $23.00 FedEx Home Delivery shipping) yesterday. Also bought the on sale $18.99 scissor jack from the local Harbor Freight store, and a collapsible 14" lug nut wrench from Walmart for $12.92, plus a 10' ratchet for $3.44 from Walmart. Also ordered the 21 1/5" cover from Amazon for $10.91 plus $5.58 shipping.
This was all inspired by just returning from driving 1,250 miles over 10 days in England & Scotland, and having an Avis car with no spare. On day 1 hit something, gauge said stop, low pressure. Tried to use the inflator/sealant, and it flowed out the sidewall. Person at a fish & chips drove us to a hotel that Sat. night. Avis roadside service tried to send a replacement tire...but 215/45-18 was not available. Sun. morning got it towed 25 miles to only Avis open that day, and got a replacement. Also without a spare! Total billed to me was $430 for the "tyre" and the tow was not charged. Filing a claim with VISA since they cover rental car damage. I didn't pay the extra collision Avis fee at rental. First rental car issue in over 40 years of rentals. So I want a spare in my C-Max for any trips outside my metro area!