[Perfectlap]

The idea of paying someone to detail your car is like paying someone to make me cold cereal in the mornig.

Unless you're dealing with a legit pro detailing shop, and there are very few, most are simply car washes with a little car waxing section. Those guys are not knowledgable and are ham fisted, they'll do more harm than good. Probably because they're paying minimum wage workers to do a technical job.

Which means that there's no escaping paying someone a fairly high price for top shelf detail work.
But at the same time an owner can do nearly all of the most common jobs performed by a legit detailer with a little practice. It's not like tyring to teach yoursefl electrical/HVAC work.

My suggestion is use a portable air-conditioner in your garage. I seem the at Costco.
Or do the work at night and use halogen lamps from Sears. I clay/wash at the same time, the suds from washing provide ample lubrication for clay barring. rinse the car off and do a quick second wash to clear any debris you might have scattered. Even on a very neglected sports car, clay barring should not take more than a few minutes per panel. The second time around will be even faster. If you are using a Flex polisher or Porter Cable waxing the car is a piece of cake.
I can do a small car like the Boxster in 20 minutes.
The only really time-consuming part of an exterior job would be de-swirling, that requires slow left to right motions for the polish to grind down the swirls. But you should only be doing this once a year or so -- the paint only has so much clear coat to spare. If you find a pro detailer, I would do all the prep work (wash/clay bar/polish ie clean) myself and ask them to simply get rid of the swirls. The final 'icing on top" stages of adding a sealant and wax topper does not require a pro detailer's steep rates. Any enthusiast can do it him/herself...unless they are physically unable or are too lazy.