Thank God , I have never had a serpentine belt fail . I have always tried to observe their condition and replace them when they became " cracked " .
I always try to keep an old belt in the trunk , just in case one does go bad . To use in such a case , as a spare , until I could source a new one .
You might consider doing that .
We purchased our 2006 Buick Lacrosse 3.8l , a couple of years ago , with ~ 36,000 true miles on it . I knew this was not enough miles to justify replacement of the " rubber products " , under the hook . But it was over 10 years old and I am getting old enough that I do not wish to do emergency repairs , out in the middle of nowhere . And there is a lot of open road in Texas . ( Especially if it could be avoided by aggressive preventative maintenance . )
I made a list and started ordering parts from RockAuto.com and purchasing parts locally . I sourced DEXCOOL , both radiator hoses , both heater hoses , serpentine belt , tstat , PCV valve , PS fluid , brake fluid , ATF Dexron 6 , hood and trunk lift struts . Dealer had changed the engine oil before we accepted delivery of the car .
Looking on the internet , I discovered the potential of the 2 plastic coolant elbows . Sourced / installed metal replacements for them , too . The old ones still looked good . ) The hoses would have probably been fine , also , but I replaced them anyway .
Replaced almost all of those parts . The tires still had good tread , so have not messed with them , yet . Turns out the serpentine belt still looked pretty good , so I re-used it & put the new one in the trunk .
Used a suction pump to suck out fluids and replaced with new fluids . Added 1 gallon of DEXCOOL , after replacing the radiator hoses .
Brake pads seem fine , have not messed with them . A/C still working fine , as of a few weeks ago . No work done on that system . Same with tires . Oil / filter has been changed a few times with dino oil ( DEXOS is not required / indicated ) at around 3000 - 4000 miles .
So far , we have made several trips in the Buick and had no problems , thankfully . I consider it money and labor well spent , DIY , for preventive maintenance .