I bought 4 new BF Goodrich tires for my 98 Accord LX 5-speed with
75,000 miles. The cars is very quiet now and very smooth. The guys at
Costco told me to get an alignment and they implied it would protect my
tire warranty. They said get an alignment every year. I think I have
had one alignment since new.

I am wondering if I really need one. There is zero vibration or shimmy
in the steering wheel.

If I take my hands off the wheel, (hold them an inch away from the
wheel & when no cars are around) the cars drives totally straight and
the wheel do not vibrate or anything.

The tires have a 60,000 mile warranty, 500 rating and Costco provides
free rotation, road hazard the works.