Well paypal has this 21 day payment hold thing they have been stuffing down sellers throat so I think that's why the seller is insisting on the rush delivery. Have you check his previous selling activity? Technically you can't back out but you can just not pay. I think you have something like 3 strikes before they ban you. Just tell the seller that you can't complete the transaction and hopefully he/she will understand.
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E92 BMW M3|Space Gray|DCT|Performance Splitters|Carbon Fiber Mirrors|Performance Spoiler
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