General Motor Corp.’s ACDelco brand is offering consumer rebates on qualifying spark plug purchases through Dec. 31, 2015. Consumers are eligible for up to $32 in rebates. Consumers must purchase a minimum of four and maximum of 16 ACDelco spark plugs (per household) at retail stores or through professional installers to be eligible. The qualifying spark plugs are: Professional Iridium, $2 each; Professional Double Platinum, $1.50 each; Rapidfire Performance Single Platinum, $1 each; and Professional Conventional, 50 cents each. ACDelco direct accounts, jobbers and ACDelco Professional Service Center Program participants may order printed rebate forms or download electronic rebate forms.