r shall be forfeited unless it shall appear that the owner or other person in charge of such conveyance was a consenting party or privy to a violation of section 2, 3 or 4; (ii) no conveyance shall be forfeited by reason of any act or omission established by the owner thereof to have been committed or omitted by any person other than such owner while such conveyance was unlawfully in the possessio