At the end of the test drive, remind the buyer of the car's asking price and how "firm" that price may be. This is also the time to revisit any remaining warranty or extended protection, or whether you're selling the vehicle "as is."
Then let the negotiations begin! Ideally you've given yourself some padding on your asking price, so let the buyer take the lead in either accepting or counter-offering.
The art of negotiation involves knowing beforehand what your lowest acceptable offer is and feeling confident that there are other buyers out there if you can't agree on a price.
If a buyer offers an amount below what you want to accept, be prepared to move along. Suggest that they contact you if they reconsider. But if they make a reasonable offer, be prepared to say yes.
If you plan to sell your car on the spot, remember to bring your title/paperwork. Finally, make sure you have a ride home (something that a lot of people forget). Next Step 10: Complete the Sale