I have a 2005 toyota solara,just bought it,how often should I changetranny fld?

Agree with everything said above, make sure you use Toyota type 4 fluid, I do mine at 30k as well.

My information system tells me that the fluid in your automatic transmission should be flushed every 60,000 miles. Typically I personally remain slightly old fashioned when it comes to transmission servicing, and recommend the service be done every 30,000 miles. I have two main reasons for more frequent fluid exchanger services. 1) It doesn't hurt to perform the service more often, the only negative is spending some extra cash. That being said, automatic transmissions are very complex units unto themselves, which is why there are so many transmission shops, almost as many as general repair shops. These units are very costly to repair and/or replace, so a little extra piece of mind is worth it, just my opinion. 2) More frequent services allow for possibly catching any upcoming problems that are just starting out. When a vehicle comes in for the servicing of the transmission, a more precise test drive devoted to putting the transmission through its paces usually takes place. Simply put, more attention is paid specifically to the automatic transmission unit above the standard fluid level and condition checking performed at your normal engine oil service interval. Hope that helps.

I was told every 50k with new filter