It's very common for leasing companies such as Enterprise to maintain their own vehicles, especially when they're on long-term lease to other companies. Indeed, the history of this Ford Transit seems quite normal. Enterprise should hold a record of the maintenance history of the van but we'd corroborate the story with the vendor before agreeing to buy it. If you're buying from a dealer then there are levels of protection in place to ensure you are not ripped off - if the dealer says it has a service history then it must be sold with one. It sounds here like the dealer is being ambiguous as the only way you can get this is from the leasing company. That said, it really is very common for ex-lease and rental vans to be maintained at the leasing companies' own service and repair depots. On its own, it wouldn't be a reason to discount a van if its otherwise well-prepared and in good order.