Should an automotive retail business use a mystery shopping solutions services?

I think yes you should, every business needs to have a mystery shopping solutions services, because if you want to improve your sales team, they need to be audited. It’s just not about how you sale your products but also how your team can approach the potential & return customer.
You can try to look into the Mystery Audit provider such as AQ Services, Bestmark, Market Force for more case studies.