In the market for a Prius, should red trangle display along with other dash lights at pre-startup

Update: ok I did go ahead and purchase this car last Tuesday. It has 2006 with 198,000 miles. It was in a minor accident with just some hood damage. I paid $2200, I am quite happy with the car so far, it is really fun to drive and see the battery charging. After over 300 miles the MFD is showing around 48mpg! The first time filling up I thought the pump kicked off early at 7.7 gallons (I was down to 1 bar on the fuel gauge) so I tried to start the pump again and it just shut off, well after the second time I finally figured out it was already full! I hope I didn't damage the bladder. I've read on hear that topping off can cause damage to it?! I normally do not top off but I could not believe this tank would only hold a little over 7 and a half gallons!
It looks like from reading on hear the first thing I should do is change the trans fluid.