The signed or draft purchase agreement, the franchise agreement, the seller's financial statements and payroll, the fund-trace records, and any escrow or financing paperwork. Send drafts before signing so clauses that harm the case can still be changed.
Order of review
Send the purchase agreement first, because it settles what the enterprise costs and whether the buyer is acquiring an operating business or a collection of assets that will need rebuilding. The franchise agreement comes second, with the owner-authority clauses flagged. Third, the seller's records for the last three years: tax filings, payroll registers, the lease, supplier contracts and any customer maintenance agreements, which together show the enterprise is real and not marginal.
Fourth, the money: statements from the account that will fund closing, records of the sale or savings that produced the funds, and every transfer and currency conversion between origin and closing. Fifth, the escrow or deposit terms and any seller note, with the security clause highlighted, because a loan secured by the dealership's own assets is not the buyer's capital at risk. A buyer who sends only a bank balance and a listing brochure has sent the two least informative documents.