Remember, depending on the CRA, auto inquiries within a 14 or 30 day window count as one inquiry. So if you rate shop and app 15 times during a 2 week period, then you only have one inquiry as read by FICO (but your report will show the 15).
Inquiry damage is overrated. It is lumped into the "new credit" portion of the FICO formula. 15 of my last 20 inquiries resulted in no score change when pulling the FICO report the day before and the day after. I did see damage to my CR for the first time this week when I added 3 inquiries on EQ and I lost 5 points off EQ. Most damage occurs when the score is closer to 750 or if your "new credit" isn't so bad (mine was not good or good).
Most people think that adding a CC will improve their score. Unless your util is super high or if your mix of credit is bad, you'll likely see a score drop up to the 20-25 point range. Some see that score drop and mentally link it back to the inquiry, which isn't true.
As Byrd mentioned, FICO doesn't care if it is a CA inquiry, a CC inquiry, a loan inquiry, a mortgage inquiry, a car inquiry, etc. An inquiry is an inquiry.
I agree that scoree damage is overrated.
Unfortunately Chase Protection ID and TrueCredit recognize the inquiries performed by Collectors in their FAKO scoring.
So will do lender during a manual review.
I would care more about not to have CA hard inquiries at any time.