Eaglecash867
Tamiya X-20A is what you should be thinning it with. Personally, I just use 99% isopropyl alcohol, but X-20A is the correct thinner for the Tamiya X and XF series of paints.
I always use LT to thin my Tamiya X and XF paints,with good results.
I'm thinking you can use LT to thin their clear also,what do you think