Lender telling us not to buy a car even AFTER closing??

[Tim Slatt]

Buying in Nevada, scheduled to close Wednesday, already received a clear to close.  We currently have no car and are renting one until this process is complete.  I was intending on purchasing one immediately after closing, but our lender is telling us to wait at least a week (??)  Am I correct in assuming once the deed is recorded and we have the keys, we're in the clear?  My only theory is he wants our mortgage to look clean until he has the chance to sell it to a big bank (it's a small private lender), and he's only looking out for the company's interests.  Any advice?  Can a lender "take back" a loan once it's closed and the deed is transferred?