Most credit scoring models have been designed to recognize when a consumer is rate shopping and avoid penalizing them. For example, the most recent FICO score ignores all mortgage or auto loan inquiry made within a 45-day window. Older versions of the FICO score use a 30-day or 14-day window. Once the "window" has passed, loan inquiries are treated as one. Whether (and when) your score will be influenced by rate shopping depends on which credit score your lender is using.
Credit inquiries make up 10% of your credit score. If you have a 700 credit score, that means the penalty for too many inquiries could be as much as 70 points. Just how much the additional loan inquiries hurt your credit score depends on how many other inquiries you have on your credit report.
