Currently, I have a primered civic hatchback. It is butt ugly, and now I want to fix it up myself.

The previous owner wanted the "flat black, rat racer look" and just slightly sanded down the OEM paint, then sprayed a coat of Rustolem black primer on it. Didn't really do anything about the rust that was already there. There was some surface rust on the hatch that I wanted to stop before it got worse, so I went to work. I got a grinder bit from homedepot for my drill and got rid of all the rust. I then sanded down the entire trunk. I then sprayed it with some rustulum primer. Sanded down that. Added more primer. Sanded down that, then added my final coat, which was Rustoum Chalkboard finish (actual paint that repels water, instead of absorbing it like the primer did) I added another coat, and then once that dried, I dry then wet sanded using 600 then 800. The final result is and almost smooth as glass finish and it actually repels water now. I am actually so pleased with the result of that one panel, I am thinking I might be able to pull off my own paintjob. I have been reading up here, and on some honda sites on how exactly to go about this.

So far, I have come up with these "steps"

wash car with dishsoap to remove oils and wax.
Mask everything, remove things like trim mirrors ect
Sand car to scuff up paint, just slightly to under the clear coat.
Fix dents to the best you can, then add body filler lightly to make completely even, then sand it down.
Spray a coat of primer.
Sand some more
Primer
sand
lightly Primer of opposite color
Sand to try and remove the opposite color. Where can't be sanded down to the coat under easily indicates a dent that should be fixed with body filler
do process again until it is all smooth.
Sand
Spray top coat
Sand?
Spray clear coat
Start with 1800 grit and work way up to 3000, then buff.

Now how do these steps sound. What grit sand paper do I use for each steps.

You are going to have to remove all the rattle can primer and paint if you are looking to use automotive finish on the car.

You will not sand your base coat as you have asked.
You can sand your clear coat if you wish.. 1500-2000 will be fine for what you are wanting.. No need for the 3000 on this project


36-80 grit for body filler
180-320 finish glaze
400-600 for final sand before base coat
1500-2000 for color sanding and buffing


BTW all that info is here in greater detail, you just have to use the search engine and look