I only had to read the first 4 lines of Northpolar's post to think Bridgestone.
Apparently they are renowned for cracking.I first had them in 2007 on my Porsche Cayman and had to replace the fronts after a few years because of crackling,mostly between the treads.The rears never got that far due to wear and punctures.(The downside of having tyres twice average width is twice as likely to get a puncture.
I sold the Porsche just after I got early retirement and bought 2 new Mazdas,CX7 (RX lookalike) and an MX5.Guess what...both had Bridgestones. The CX7 did most of the mileage,so cracking didn't have time to occur.The MX5 kept the original tyres for 10 years with no cracking at all.Both I and the dealer kept a close eye on them in later years just in case.
A year ago,almost to the day,I bought the RC,with Bridgestones.......
I can't get away from them...