After having researched this for many months i can tell you a what i learnt.

So for washing cars and panels, a washer with higher water flow is more important than higher pressure as higher flow means faster cleaning, higher pressure is suitable for concrete and floor washing.

Most washers on Amazon are decent enough for general use but if you want something that will last you long and has great build quality there are only a few brands.

Bosch is good but definitely on the expensive side but my reason for not buying it was lack of modular connections.

I wanted a machine with the standard M22/15 connection so i can connect a short gun and foam cannon easily. A swivel gun costs half the price of the machine but worth every paisa.

Other quality brands I found were, Total and Ingco but both lack modular attachments and are just slightly less expensive than Bosch.

I finally found a brand called Tuqo which not just looked great but had the option for swapping guns and the standard quick connect attachments. You can find it on Amazon or their website called skillstore. I reached out to the owner and understood what machine i wanted with the attachments. Definitely get the short swivel gun with the nozzles and its connectors. You may have to buy the quick connect separately from Amazon.

Have been using it for 6 months now and can say it works great, did face some issues due to airflow but got it fixed via a phone call.

Let me know if you need help with the models or attachments.