Smoothing plastic trim panels

Hello, over the past few months off and on I've been redoing a 1999 Silverado. So far The engines been fully machined/balanced, new cam/pistons/etc giving it PLENTY of power (417hp from a 4.3L V6). I then moved on to some minor exterior mod's like filling in the stake pockets, tailgate trim , tailgate handle , billet grill. Rims and a drop will have to wait (building this on a budget). Moving onto the interior i decided to smooth all the plastic pieces. Seeing as the texture on them wasnt to deep I decided to sand them down using 360grit i had lyin around. Although this worked great , it takes ALOT of time and patience for every curve and panel.

Is there an easier way to remove/fill in the texture area ?

I was thinking bout trying a Smooth spot putty but figured id hold off for now till i find the easiest way.

My buddy that works at a body shop was telling me that there is some sort of chemical they use to smooth out the panels before paint. I think it chemically melts the texture off then they just smooth it out, I'll try to find out more...