This is something that should run through the design validation.
Most of the cars in Germany use Immersion Tin for the entertainment PCB's
with a leadfree no clean paste and SAC305 with an alcohol based flux.
Does the PCB supplier change? Another risk.
Have this finish been used before on a similar product?

There have been some nasty surprises along the way.
Your product in your environment needs to be checked out.
Some involving flux, coatings, and specific applications.
The extended validation found most of the problems.

Last minute changes in PCB finish and suppliers with insufficient testing
has cost 10's of million of dollars. Just part of the cost of
implementation of Lead Free.

If an EMS is used, there can be even more surprises.


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________