Even the E39 does that. It's all programmable. If you have the high OBD like on some E39 and if it is programmed to be active, you'll hear, see, notice 3 things (in a E39 high OBD):
1. Hear continuous "gong" on alerting you to fasten up.
2. See the "wear seat belt" light on.
3. Read the" Fasten seatbelt" message on the OBD cluster.
Even the E39 does that. It's all programmable. If you have the high OBD like on some E39 and if it is programmed to be active, you'll hear, see, notice 3 things (in a E39 high OBD):
1. Hear continuous "gong" on alerting you to fasten up.
2. See the "wear seat belt" light on.
3. Read the" Fasten seatbelt" message on the OBD cluster.