Nice car! Old automobiles are great objects for photographying but in this photo it seems that the quality of light was not the best possible - colours seems to lack depth. It seems that it was a sunny weather and car was in a shade, which are quite bad conditions to make good photos. If possible I think you should take a second try on a half cloudy or lightly overcast day or if sun is shining try early in the morning. If light is bad no software or using RAW can rescue the colours. Also I think you should go closer to subject or crop that lawn away for the most part. No the grass occupies too much area in this photo which does not make sense since it does not have any meaningful information.
Best regards, Pekka.