2005 prius

Hey guys, im new here and after reading some really good posts decided to join and post my self.

I recently purchased an 05 t3 prius with 1 previous owner and 70000miles on the clock(company car). Its in perfect condition and nothing wrong with it so far (apart from the front tires badly worn, which i sorted). I got what i think price wise quite a good deal compared to the prices around but obviously have been stung by 70000 miles in 3 years. The car has full service history and am taking it in for a service this week.

My question is, is there anything that I need to watch out for on a car with this mileage and have I really got a good deal or is there going to be an even bigger sting coming my way and when i take i for a service what should i get done and what should i avoid, as ive been reading alot of ppl saying the dealers try to sell unnecsary checks and replacements

Also is there any chance of getting an extended warranty on this car now?

Thanks very much, and am looking forward to your replys

p.s only today i noticed when I got home and parked, a red car warning light came on, I read in the manual this is for the immobiliser but have never noticed it before. Any ideas?