A couple minutes on cl, autotrader will let you find multiple 2019 740is with less than 30k miles for sale for around $45k, half the original MSRP. Equivalent S550s or A8s are a good $20k more. Is there a reason why these depreciate so much more than their peers?
Having a new model out will do that
The update is just a facelift, not a new model…
Either way, it’s something that sets the 2019s apart as being the old model.
Supply and demand.
S Class has a higher base price.
Audi A8 depreciates just as bad.
First year depreciation is always the worst. Why do you think there’s no 12mo leases? If there was, It would almost be cheaper than renting.
What about after ten years? LOL
There are several 2019 740is for under $45k with 30k miles or less, no present generation A8 comes close ($56k) and S550 is even further away ($69k). Those are vastly different numbers for similar cars.
Maybe because the corporate fleet program? Probably BMWFS were paid good by big corps or entertainment/hotel industry, so once they came back they just discount them heavily and let go.
I was looking into CPO 640i GT and most of them were like that. They were at low $40s even $3xxxx vs $75K+ MSRP
The 740s look like they take a much bigger hit than 750s in the first year.
740s on CarGurus within 500 miles of me start at $38,500 (ad price) for an example with 37,000 miles.
Lowest priced 750 has 10,000 miles for $65,000.
If Bmw was in the same class as Benz or Audi you would see similar lease deals. Bmw is blatantly cheapening their brand, and it’s reflected in the deals we see here as well as depreciation. Benz and Audi has much better tech and performance.
Marketing 101, have a high msrp, then discount it to make people think they’re getting a deal. It’s all psychological.
The 740is for sale do seem to be mostly fleet vehicles which is probably a good thing? And yes, it is really just the entry level 740i that is affected this much but that may make it a bargain to buy and own, given that you tend to have a lot of the basic warranty (4y/50k miles) left. Best case scenario for a 3y lease on a luxury vehicle is likely the IS300 which still sets you back about $15k (DAS, payments, taxes) so a 740i might not be far off over 3 years in total cost (taxes, depreciation).
Considering I paid $62K for my $95K sticker on my 2019 740i I am not surprised. The residual is $48K and it will be no where near that.
Then again a lot of those cars you are seeing are really base model 740’s with stickers in the mid to low 80’s. So if someone paid $20K off sticker or $60K then they only dropped $15K in first year. Really if they have close to 30K in miles they are probably 2 years old. So maybe $15-20K in 2 years time. Never pay anywhere near sticker and lease so you have an option at the end. Oh and stay under warranty. 
Overinflated MSRPs on Audi and BMW sedans
No one wants out of warranty or soon to be out of warranty German luxury cars
A8 /7 series /Tesla buyers want status and prefer “new” cars
Someone with access to a playbook could shed some light here in a hurry…
In short though, fleet and limo incentives are insane on these cars so it’s really no wonder they’re not worth much on the secondhand market.
I was originally planning to buy a used 7 Series roughly at dealer cost through a personal contact, but nearly every one that came up on Manheim that looked appealing on the surface had a fleet/livery notation on the vehicle history.
I normally purchase and drive vehicles for several years, an approach I wasn’t willing to take with someone’s old Uber Black car.
Had no idea that BMW sold many 7-series base model fleet vehicles. The Nissan of German luxury sedans!