Hey all,
I posted last week re. having problems with new tires from Costco tire
center, and got some good advice here.  Wanted to let you know how it
turned out:

To recap:  I bought a set of 4 BF Goodrich Premier Touring tires from
Costco.  The car shook after I got those new tires.  With 150 miles on
the tires, one of the tires went completely flat.  The Costco tire
center employee refused to evaluate the tire, insisting that it is
"normal" for tires to go completely flat at any time.  Finally he
agreed to evaluate the tire (seal between the tire and wheel was poor)
after I gave him a hard time.  Because the car was shaking, I had
asked him to check the balance and he also refused, saying that the
balance definitely was perfect.  He also insisted that the tires were
perfect, and said things like "when did you last get an alignment?
You need to get an alignment at least once a year" etc.

Later I took the car to a different Costco tire center; they checked
the balance and said it was ok, but the car still shook a bit.

Later I re-mounted the tires myself per Ray O's suggestion and the car
no longer shook, suggesting poorly torqued lug nuts initially.  With
the car not shaking I noticed that the tires rode very rough and
noisily.

Figured that either the tires are defective or are just poorly
designed to begin with.  I emailed Costco's online tire center, since
that's where the tires were shipped from.  I complained that the tire
center employee was dishonest, and that the quality of the tires
seemed poor, and I did not know how to proceed.

Costco online said they forwarded my email to the regional tire
manager.  A couple days later I got a call from the store manager of
the Costco where I'd gotten those tires installed.  I told him my
primary concern was that his tire center employee was dishonest with
me by insisting that people's tires go flat on them all the time, and
that this is normal and doesn't warrant a look.  I also told the
manager I was unhappy that his employee refused to check the tires'
balance, and that as a result of his employee's dishonesty I wasted a
lot of time.  Also I told him it's a liability issue for the store if
his tire center employee is dishonest and is refusing to evaluate tire
installations that are clearly defective.  The Costco manager was
friendly but was not that apologetic and said things like "the tire
center employee must have just been having a busy day" "he must have
been having a bad day" "I have spoken to him and he knows not to turn
away customers' concerns in the future."  The manager said that his
"regional tire manager" told him that these tires are "budget tires"
and are supposed to be rough and noisy.  He offered to have me get the
tires replaced with the same type-- I said I would go to a different
Costco location since I didn't trust his tire shop-- he said ok and
made arrangements with a local Costco for this.

Anyways, I got the old tires removed, and a new set of BF Goodrich
Premier Touring tires installed tonight, and now the car rides very
smoothly and quietly.  I asked the tire center employee if he thought
that more expensive tires would ride more quietly, and he said no, he
didn't think so, and said that cheaper tires have a thinner sidewall
so often are quieter.

Bottom line-- the first set of tires was either defective and/or had a
defective installation too, causing them to be rough and noisy.  So,
if something similar happens to any of you in the future, it's worth
swapping the tires with the same kind, in case you received a
defective set the first time around.

Thanks again everyone!
John