I also have istalled acar and i would buy pro version but the interface has stopped me. Acar is a great app but has a bad and old design.
Next version (5) will have new design? Do you have any preview or mockups?
We do plan on retooling the design of aCar in a future update. The Team is working on ensuring integration with Fuelly and GasCubby will go smoothly, and then we can get to the fun stuff!
No previews to share at this time. But, maybe soon!