I drive a 2002 Acura and my Attorney advised me to buy a car before I filed because of the cheaper APRs. Cars do not last forever. He said the courts are generally understanding, if you are buying something modest and it is your primary mode of transportation.
The only thing that I can think of is the cap on exemptions. Do you know what the total amount of exemptions that are allowed in your state? If the value of your car and other exemptions are less, it should not be a problem. They may want to know where the money came from to make sure you were not hiding it at the time of filing.
Lastly, I'm not a lawyer. YMMV. Nolo.Com has a lot of good information
Sounds like you are in a really good spot then. Congrats on the newer car.