HELP - Need some real-world carrier direction on a garage risk in...

HELP - Need some real-world carrier direction on a garage risk in Colorado. Client is an auto repair shop (no sales). They perform repairs, test drive vehicles on a frontage road/freeway after repairs. Employees are driving customer vehicles (non-owned autos). GL = auto exclusion (no help). Garage keepers = only covers the customer's car, not liability to others. Progressive + GEICO = both declined for this exposure. Looking for carriers comfortable with non-owned auto exposure for repair shops willing to cover road testing (including freeway use). Ideally commercial auto with Symbol 9 or garage form that properly contemplates this. Who are you placing this with right now (admitted or E&S)? Feels like a super common exposure but weirdly hard to place cleanly.