[coolnight]

Yes I believe that your assumption is right, in that the clearcoat your using is likely too "hot" for the acrylics. What kind of clearcoat are you using?

You could go on using the acrylics once you've found a suitable clear for them, however I must ask, is using lacquers an option?

If it is I highly suggest making the switch. I personally recommend the Tamiya TS lacquers if they are available in your country. They are SOOO easy to use and have a wide assortment of colors to choose from. Nowadays, I don't use anything else to paint car bodies.