You lot aint helping, the Wife is a Merc fan for some reason.
I'd probably not get something crazy like CL500 though, despite wanting one, probably go all sensible and 'dad mode' and get Facelifted W211 E320 CDI estate.
Although who knows what they will do with London ULEZ, just a minor change to current 2021 plans mean big changes in my choice of commuter hack.
Anything decent from MB is going to be a bit older than the Omega, and will require loving, which we already know you CBA with. Also, being older, will get hit with emissions wank.
I could almost forgive the CLS500's minging looks and poor build because its a nice engine... ...in the same way I could forgive the BMW badge on a (real) M5.
I think the first point will drive you towards something dull, reasonably economical and ultra reliable like an Insignificant or very late Mundano (early ones plagued with electrical issues). Unless the badge is more important than anything else, which I suspect it might be