u forget that the spares function isnt just as a backup. its a vital part of the crumle zone of ur car. u may not know it, but that spare is strategically placed in order to absorb much of the impact. by removing it, ur rear is way more vulenrable to a rear end collision... ur bumper only works good cause it has that spare to reinforce it. sure its good to remove the spare when draggin or autocrossing, but for daily driving, its jus not worth it to remove it.
(pick 2 of the three only)