Which device for 2018 A4

I purchased a VCDS connector for my 2013 Passat TDI but with the TDI going to the TDI graveyard in the sky I am wondering if I can use the same connector for the new Audi A4 I will be buying this week or do I need to upgrade to another device connector? Thanks for the information

On a 2018 model I suspect you would need either a HEX-V2 or HEX-NET to be able to scan all the modules and get complete diagnostic details.

Ross-Tech do offer an upgrade path, see https://store.ross-tech.com/shop/cat/vcds/intup/

If the interface you have is a HUC, the easiest option would be to plug it in (even if incompatible it won't do any harm) and run an Auto Scan.
The scan output will tell you if it encounters modules that are unsupported with your interface.

Busydiver has a Micro-CAN. It's not compatible with a 2018 A4 at all.

He can get a discounted, trade-in upgrade to a HEX-V2 or HEX-NET here:
https://store.ross-tech.com/shop/RetHEX

-Uwe-