It's your car, so really it's your call.
Technically, it should have a matching wheel and tire for a spare (no trim ring or cap) but as you say it will be covered up anyway.
My GTO, which I don't drive, came with a rally I for a spare.
For my Grand Prix, which I drive the daylights out of, I bought the cheapest, blackest tire I could find, mounted it on an extra 8 lug steel rim and threw it in the trunk. I also have a small hydraulic floor jack rather than the bumper jack, and a separate set of tools (breaker bar and sockets) should I ever need it.
So, basically, put me down for "one vote for each"...
K
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'63 LeMans Convertible
'63 Grand Prix
'65 GTO - original, unrestored, Dad was original owner, 5000 original mile Royal Pontiac factory racer
'74 Chevelle - original owner, 9.56 @ 139 mph best
http://www.superchevy.com/features/s...hevy-chevelle/
My Pontiac Story: http://forums.maxperformanceinc.com/...d.php?t=560524
"Intro from an old Assembly Plant Guy":http://67-72chevytrucks.com/vboard/s...d.php?t=342926