With new cars having can bus wiring systems, fitting an after market tow bar can be complicated and costly.
When I bought my new car I had a factory fitted tow bar installed which cost a not inconsiderable £750, but as I was sure I would want a tow bar bike rack at some point and have a motorcycle trailer I thought it best to get it done.
All three of my bikes have easily removed batteries. The only one I have carried so far has been an old heavy rear hub bike with a silverfish battery. I remove both the battery and the seat post and saddle.
I bought a cheap but recommended tow bar rack which has worked very well. It carries the bike very securely with no rattling. Compared with other bike racks it seems very good value. The 45kg weight limit would only be just enough for two ebikes and you would need to remove the batteries. I remove the seat post and saddle on my old rear hub as it is very easy and reduces wind drag, but for reducing weight it is the battery that needs to be removed. You also need to be able to dead lift the bikes on to this rack. However withing these limitations, if you are on a budget, it is very good.
https://www.amazon.co.uk/gp/product/B006WNC5NE/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
I had a nasty surprise when I tried to use my old light board as the new tow bar electric plug on my new car has more electrical pins and was not compatible. This is where the complication of the can bus system showed, as when I plugged in my old light board the car refused to reverse as the rear parking sensors remained live and sensed there was an obstruction and applied the brakes when I tried to reverse.
Once I bought a modern light board and plugged that in, all was well.
Complication for complications sake seems to be the modern way.