 Proposition 2½ lowered this rate to $25.00 per $1,000 of car valuation, resulting in a 2½ per cent excise tax rate, but can still increase 264%, to the previous 6.6% tax rate if a Proposition 2½ operational override (see below) is approved by ballot in a community during a general (or special referendum) election.Proposition 2½ excludes four cases from the limitation on tax levy increases