Summarize this article:

At the very least, you should clean all surfaces of your vehicle, vacuum it, wash the exterior, and remove any garbage or crud that might have accumulated over the course of your ownership. If this sounds unappealing, you can always take your car to be detailed by a professional. These fixtures are frequently affordable to replace and will be among the things buyers are on the lookout for. Most auto supply stores will have the parts you need in stock, and most fixes will require little more than a Phillips screwdriver. Though you might think a small crack or chip inconsequential, these are hard to miss for new buyers inspecting the car for the first time. And when that new buyer notices this defect, he'll likely try to bargain you down from your asking price far below what the repair would cost you. A dealership might knock off as much as $800 for a "new windshield," as this might be the factory cost, whereas your insurance might cover most, if not all, of the cost of this repair. Brakes are a tremendously strong selling point, and mentioning to interested parties that you've recently had the brakes replaced will up the value in their estimation. For most cars, this will only cost $100-$150, and could serve you well in the bargaining phase. You might be able to get several dents in the body of your car repaired for around $100. A "like new" body will up the value of your car, and if the potential buyer doesn't see the ding, he won't be able to use it as ammunition in negotiations. Tyres can be expensive, but making sure your tyres are ideal for your sale can cost less than you might think. Buyers will check your car's tyres for worn down or uneven tread. Replacing one or two trouble tyres with matching used ones, which should average you around $30-$40, can save you from a $300 - $700 deduction a buyer might request to offset the cost of new tyres.

Summary:
Prepare your car for sale. Improve the condition of your lights. Contemplate windshield repair. Make sure your brakes are in good condition. Touch up dings and dents. Examine your treads.