It’s always worth asking directly. You’re more likely to get a more positive result by doing this face to face rather than on the phone.
We got a discount on a pack in an Audi Q3, 50% off if I remember correctly but this was 8 years ago and on a stock car.
By the way, Advanced Payments are not non negotiable but many dealers are reluctant to offer a discount. Some do though, so keep an eye on the sticky thread about the latest offers.
2024 - BMW i4 Grand Coupe eDrive 35 Sport
2020 - Volvo XC40 T4 Inscription
2017 - Audi Q3 TFSi Sport S-Tronic