This reminds me, I painted an entire tailgate on a Ranger I had one time with rattle cans. I sanded, primed sanded, painted, sanded, cleared (also rattle can) and then wet sanded the clear. It lasted until I sold it (YEARS) and I swear you could not tell it was rattle can. It was literally as good as OEM as far as the surface finish. I am no more a painter then you are but I guess I just got lucky somehow with temperature, humidity and good cans of paint and it worked somehow. I have no explanation for it. I think a lot of bad rattle paint projects is due to old or bad paint cans themselves personally. Anyway, It may last longer than you think!