100% with everyone on the Bmw front. I’ve a 2005 E61 535d and it’s the best machine for towing. Air suspension that levels out nicely regardless of what you have on the towbar.
I would say, I bought mine in 2020 for £3k, probably spent another £2k sorting all the normal issues. Look for one that’s been in same family or owner, it’ll be well cared for and it will do over 300k without any problems. The earlier 2005 and before have a cast block and are said to be the best, no timing chain issues with these. Dont be put off even if it is tapping. The 6 pots are not too bad to do the chains, under a grand.
Bought mine with 103k miles, had to do the torque convertor and all the thermostats. Thermostats will fail and bmw in their wisdom don’t display the temps. You get a reader that shows or you can see in hidden menu. Get a small Bluetooth adapter and an app such as bimmercode bimmerlink and it will show temps. When you go check a car get it upto temp and see it’s getting upto 90deg or thereabouts. I use this one and have done for years
https://amzn.eu/d/05r7W6WE
If temps sitting at 70 it means the thermostat is buggered. If it’s gone unnoticed then the TC can slip as car never getting to temp. Sussex autos can sort it out, great idea to do the gearbox service at same time.
That and you’ll be good for 100k no bother.
I’ve got Ista-D and it’s so useful, you can get a copy on the various forums.
Great comfy car that will tow all day long. Lots of toys even on the old ones. Mines got adaptive cruise, adaptive headlights and pan roof. Everything still works after 21yrs..
I’ve also got a newer saloon 2016 last of the F10 530d great cars..