Short Answer
Dealers/Vendors should go Toll-Free now if dead in the water with 10DLC. If not, get a TFN verified anyway as a back up.
Long term, ensuring each rooftop is registered as its own "brand" with a "low-volume mixed" campaign should be the best practice.
Long Answer
For the last 2 years, I have consistently kept software platforms safe with Toll-Free (TFN) being a direct replacement for any use case that would default to 10DLC.
Reasons to replace 10DLC with TFN
1. Simple, scalable verification effort
2. Registration framework isolates to the number...meaning you diversify your risk with any blocks..so even if you do get filtered there is better damage control than your entire 10DLC campaign getting blocked. Do TFNs get filtered less? Not really.
3. It retains all functionality that a 10DLC number has (SMS, MMS, Voice)...I push a large quantity of MMS from the TFNs I've spun up.
4. End users don't care about a local number as much as businesses seem to think
Disclaimer - Between now and the end of the year, there WILL be delays in TFN verification. Expect things to return to normal pace in Jan/Feb.
Short Codes
I wouldn't consider these a direct replacement for 10DLC, but a solid alternative for a high volume SMS/MMS only use case. Voice is not supported on Short Codes.
If you have an engaged partner that can coach you on the Program Brief, you can get that approval process down to 1 month.
Once approved, you are far less subject to the surprise blocks/filtering that other number types have.
So yes, you could avoid headache if you're willing to pay the higher monthly to set and forget.
TFN
Yes and No. It is the number that needs to be verified. Not so much the business in this case.
A business may have up to 5 TFNs that points to the same URL in the verification brief, but needs a "valid business reason". Examples - testing, sales, service, etc.
10DLC
It depends.
If Clocktower Auto is a vetted brand with a "low volume mixed" campaign under it, you can just add numbers to that campaign.
If not, how you set up the brands and campaigns could come into play.
Feel free to DM me with how you set it up and I can give insight.