Porsche of Wallingford is a Participating Dealer of the Instant Cash Offer available through Kelly Blue Book. The Instant Cash Offer is a trusted way to trade in or sell your vehicle, based on dependable Blue Book numbers. The Instant Cash Offer is dependent on specifics of the vehicle and must be verified by Porsche of Wallingford. If you would like to participate Please fill out the form below and stop by Porsche of Wallingford to redeem your offer. Note: Offer is valid for 3 days (not including Sundays).