I'm like Jocko - I quite like cleaning the car on therapeutic grounds but in this weather? No thanks. On car detailing sites - like detailing world - you'll find people arguing that taking your car to a hand car wash is tantamount to cleaning it with coarse grade sandpaper!
One of my neighbours is very fussy about his cars - gets a new one every 3 years and they are cleaned every 2 weeks. A bad back put paid to doing it himself so he uses the East Europeans down at Tesco. His cars always look good. I've been watching them in action at Tesco and, to be fair, they use Autoglym stuff, use plenty of water and have a bin for putting cloths in if they drop them. I had a gold service back in November for £15 - outside done, inside hovered, all other inside surfaces treated and polished including the air vents and they used AutoGlym Aqua Wax in the drying process.
I've got a voucher for £10 off a platinum wash - even includes a polish with Autoglym Super Resin Polish. £25 with the voucher - might just go for it!