I still haven't had to change tires yet so no comment there other than the obvious, shop around and compare.
In regards to insurance I've always used online sites to get quotes form multiple carriers and then compared them side by side for the best deal based on price and coverage, the truth is rates can vary a lot from one carrier to another depending on your current situation, age etc. Different companies often focus on different demographics, so you really need to get at least 5 quotes, bare minimum 3, from your local area. Specialists can be good, but in my experience they tend to be more expensive, still that might just be where I am.
If I don't already know too much about the company with the best quote, I make sure I research them online before going with them to see what others are saying.
You could go to each insurance site one by one, but The last time I used
http://AutoInsuranceDealHunter.com, there are a lot of others out there too, I've used others in the past also, pretty similar really.
