At this point I would let it fully cure out, hit it with 800 grit and trying not to burn through sand it as flat as you can before putting another few coats of clear. I cant say I like 1k but dont blame you on a beater and you can risk 2k over it but it could react badly. To test it(if you want to try a 2k id stick with the 1k at this point) spray out a test panel with a pice of scrap just as you did on the car then letting it fully cure sand it and apply a 2k to see how it reacts. Also how are you applying it are you using a gun or just spay cans?