UPDATE 2-America's Car-Mart Q3 profit rises

* Q3 EPS 31 cents vs 28 cents last year

* Rev $73.5 mln vs $71.1 mln a year ago

* Shares jump 18 pct (Recasts, adds conference call details, share movement)

March 3 (Reuters) - Auto retailer and financer America's Car-Mart Inc (CRMT.O) posted a 6 percent rise in third-quarter profit, boosted by higher selling prices and interest income, and a strong business model that continues to resist the economic downturn.

Shares of the Bentonville, Arkansas-based company rose 18 percent to $11.60, before paring gains to trade up 22 cents at $10.08 Tuesday afternoon on Nasdaq.

The company said it expects cash flows to continue to be strong in the fourth quarter as it receives special payments under the "zero down" tax refund promotion, which began in November.

America's Car-Mart, which helps people with limited credit histories buy used cars, is running a deferred down-payment program where payments from customers are scheduled to coincide with their tax refund receipts.

"We do expect to finish this year significantly higher after receipt of all the tax refunds," Chief Executive William Henderson said in a conference call with analysts.

Under its "buy-here, pay-here" business model, the company sells cheap cars, and gives loans, to customers who cannot avail traditional sources of credit, making the business resistant to an economic downturn.