<font color='#000000'>Check your suspension.  Since you have a convertible, this may not apply.  But, my shocks squeak when its below freezing out, then when they warm up after some driving, they stop.  So, you might want to put it outside overnight and see if the shocks are acting up.  I'm no mechanic, so this might be way off.  Good luck</font>

 

<font color='#000000'>My 86 Celica has some carzy noise also. And i found out it is the spare tire locking thingy that is making the noise. I put some WD-40 on it and it stoped the squeaking. So maybe it is the spare tire in your trunk.

Hope this helps</font>

 

<font color='#810541'>I KNOW, I KNOW!
i have a 93 GT coupe, after i replaced my horribly worn rear struts, i had that same noise for a day or two, when i turned right especially, ...... checked it out and found that the drvr side upper strut mount wasn't properly lubed and it also was coming from where the Spring sits againts the Strut, the spring was slightly off  the groove, fixed those and it went away.......... if that doesn't happen to be it, it may be time for new rear struts or have some one check the anti-sway bar or indepentdent suspensions connecting bushings btwn the tie-rod and the strut. I GUARANTEE its gotta be one of those things</font>