I’m happy to see that you’ve gone out and purchased a filter. The star filter is one of those tools in photography that needs to be used with care. It’s like photoshop it can be overused. When filters and photoshop are abused the quality of the image can certainly decline…
The star filter can really enhance certain images and yet in other cases it totally overwhelms the image.
Take these two photographs as an example…
The first photograph shows this type of filter being used to enhance the image:
photo by pierre_tourigny
This second photograph is a bit much and the filter has overwhelmed the image and taken over:
photo by Mazda6 (Tor)
So be aware of your use with this filter… It can be too much!
In your photos in particular I would suggest that your usage of the filter might be a little bit too much. In one image I can barely see that it’s a car in the frame. Try playing around with your exposure and try out different environments to shoot in with this filter. You’ll get better at it don’t worry.
The main thing here is that you’ve started to play with filters and that’s great!
Also keep in mind that you duplicate the look of a filter in photoshop although it will never be the same as using an actual filter.