what are your thoughts on running tires made by different manufacturers? for example, running toyos t1-s up front and s-03s in the rear?

 

I do it. I run Bridgstone GTIII's in the front and Yokohama is in the back. I just like a good turning
tire up front and a good straight speed tire in the rear. It works well for drifting too.

 

I wouldn't recommend this at all.

The two tires have different grip levels and handling characteristics in both wet and dry. Two different tires on the same car is a recipe for wierd and unpredictable handling at the limit.