Very much dealer dependant, to many your an inconvenience with a brand new one never mind older cars to others they bend over backwards.Im not sure if this is actually true but I was once told that if your BMW is more than 3 years old then you get a less than premium experience.
When I take my e38 into Blue Bell BMW Crewe I get treated absolutely fine even though it’s 18years old, same group different dealer from my local one (Knights Stoke-on-Trent) which just isn’t interested just wants volume through both sales and service.
Back in the day my father was still taking his e39 to BMW at 10+ years old and getting 750iL’s and M5’s as courtesy cars, the dealer was relatively small back then (Howarth Newcastle-under-Lyme, formerly Hartshill BMW) and they couldn’t do enough for you, once that dealer was sold and morphed into the massive Knights site the service went down the pan.
He now drives a Mercedes and the service he gets from his dealer (MB Stoke) is great, they put Knights to shame.
Ironically all the above dealers I’ve referred to are part of the Lookers group yet the service/experience varies wildly between sites so ultimately it’s down to local management.