I do it myself at home (for 15 years now) which is why the paint is still in great condition with minimum swirl marks. Though I don't wash it often. Maybe once in 2-3 months. I'd rather it look a bit dirty than have permanent paint damage from car washes. Whenever I want/need it to look great, I wash it.
Rain mostly. But we don't get that much rain here and we have had water restrictions for longer than I can remember where the municipal by-laws has made it illegal to use a hose pipe.
But I take it to a car wash every 4-6 months which does a "hand wash" I guess plus power sprayer type of thing at my filling station. Pay a bit extra for them to do a quick polish - not great work, but better than nothing I guess.
This includes the inside vacuum and cleaning.
Used to wash with the kids helping but they are too far away now so I either wash it myself if I want a proper job (wash, wax, leather care, tyres, plastics etc each get their own attention) or get the security guard at work to give it a wash for R50.