This fixes an unstable automated test in the email marketing editor so it produces consistent results. The change helps maintain confidence in future updates by reducing false test failures without changing customer-facing behavior.

The Belgian salary package simulation now avoids wrongly treating an existing contract as having a new car. This prevents incorrect benefit and depreciation values, helping employees and HR teams see more accurate wishlist salary simulations.

Following [#enterprise/60947](https://github.com/odoo/enterprise/pull/61042) , after neutralizing the field new_car, this had an effect on the wishlist simulation since the new wishlist contract considered that this contract had a new car, leading to an atn and a depreciated cost of 0