Is paying rent your priority?

My hubby just informed me that he has been saving to get me a car and the guy selling it is letting it go cheap and he needs to get rid of it soon. Therefore my hubby thinks we should let our rent slide to put the money towards this car. Rent will be overdue by 2 months if this happens! I've tried to talk him out of it but I'm not having much luck. Any ideas how to handle this with him and how do I explain this to our landlord? Please help!