hmmm...
Did you check the tutorials?
Looking at this shot (looks like you tried to combine everything you wanted to show in it), what stands out the most is the car's missing some portions.
You have to be careful when selecting the car to copy it to it's own layer, to zoom in pretty much, and making lots of clicks so the car's shape is perfectly selected.
Also, before blurring, you have to delete the car from that layer, so it's not blurred altogether with the scenery.
Check 440 CHARGER's tutorial on this matter (top of the galleries page), much better explained and with a lot more info.
If you still have problems, write them here and me or any other member will explain as best as we can. 👍
On the cleanup part, there's not much comment to make, as the car's mostly blurred.
You should try it on a phototravel shot, with a simple-lined car.