In the past, whenever I changed the timing belts on my Toyota's with over 100K miles, I also changed the upper and lower radiator hoses. This was a PM since I had the radiator off and this was a convenient time to do it. Have any of you had any problems with your hoses leaking on your Lexus'? These hoses look like they'll last forever and replacing them may not be necessary until say 200K miles. I did a search and didn't see any threads on this subject. Comments?