Car prices are compliments to gas prices. When gas prices are lower people will be more likely to buy cars because the complimentary cost of cars (gas) will be lower. Demand will increase and this will cause quantity sold to increase as well, ceteris paribus. If gas prices increase, car sales will decrease.
Yes, I believe car sales will increase with the decline in gas prices. Many people chose public transportation as a means of getting to and from school/work. With the price of gas falling, having your own personal transportation would be more affordable. Also, with income tax season right around the corner, not only will gas be more affordable, funds for a new car will be readily at hand as well.
I think that car sales going down even slightly was due more to the economy than to high gas prices. I also believe that people are going to wait for a while before jumping into any big purchases like a car. Gas prices can go back up just as quickly as they went down.
No, car sales will not increase now that gas prices are falling, because cars are still expensive. We have not recovered from the recession like we think we have. Rather, we have just gotten used to a new normal and a lower standard of living. People cannot afford cars any easier than they could before.
I don't believe that falling gas prices will show dramatic increase in car sales. Today people consider many other factors when buying the car and gas is not the only one. After all, it doesn't necessarily mean that gas will stay this low for very long time so people who are more sensitive to spending money will think hard before buying car because gas prices.