Q: What tools do I need to perform prepurchase inspection?

The threshold issue in entering the inspection business is NOT a "particular" complement of tools but rather whether you have the specific and intensive training that is required to carry out a meaningful inspection AND convey the results in an effective (intelligible) way to your customer. Furthermore, some of the pre-purchase inspection can involve records checks and advice to the consumer as to the historical reliability of the vehicle model itself and this requires familiarity with a whole range of databases and information resources. Inspections are not a highly "tool-intensive" operation as you are NOT performing repairs. Frankly, in comparison to the required training, that is the required knowledge base to perform an optimal inspection, the tools are the LEAST important requirement as anybody can buy tools but NOT "anybody" knows WHAT to look for and how to make an intelligent assessment of a very complicated piece of machinery, look at the history of the machinery, and pick up on tell tale signs of damage, excess wear and abuse. If you are already past that point - that is, you have stellar training and you know WHAT to look for and WHERE to get relevant data - the tools are simply identical to that used in repairs and their use will depend on the as found condition of the vehicle being inspected AND the extent to which your customer is willing to pay to disassemble various vehicle components to do what could become a frankly "forensic" exam (inspection types vary, although most are standard and mundane, but still quite effective). Put simply, the tools are the least of the problem, because mechanics already have them, and inspections are principally a KNOWLEDGE-based endeavor.