Residual value on luxury cars is typically poor, because part of the justification for the price premium on a luxury car is being seen in something impressive, and a 3-year-old car is no longer so impressive.

So saying "for the same residual value percentage as the iconic Mercedes S Class, one of the finest premium sedans in the world" is honest but kind of deceptive. You'd much rather have the same residual value percentage as the much less expensive Jeep Wrangler.

This is basically a lease, phrased as a sale with the option to sell back, to take advantage of incentives that governments give to buyers but not lessees of electric cars. A nice option, but hardly worthy of the breathless marketing hype.

Residual value on luxury cars is mainly bad because the maintenance costs on a luxury brand cars quickly go into the stratosphere after the factory warranty runs out. When the warranty is running out, you're hitting time for new tires, brakes, etc. It all raises the cost of a second hand BMW to be almost as high as a brand new one.

The way to "hack" this is to either stop going to the dealer after your luxury car goes out of warranty and find an independent mechanic or work on your car yourself. Both have their own drawbacks, but it's generally what you see most long term luxury car owners doing.