This is the age-old struggle for those that have moved beyond simple detail sprays and obsessed over maintaining the finish of the paint as safely as possible for the long run. Your best bet is going to be OPTIMUM NO RINSE diluted into a bucket of water along with several fresh MICROFIBER TOWELS (these make great rinseless wash towels). Then use a bottle of OPTIMUM OPTI-CLEAN as a pre-spray.
Process:
1. Prepare ONR in bucket of water: 3 capfuls with 3 gallons of water.
2. Submerge 8+ plush microfiber towels in the solution.
3. Pre-soak the section you want to clean first with Opti-Clean. Spray liberally.
4. Take a towel from the bucket and wring it out a little, then fold into fourths. Start wiping and flipping to a fresh side of the towel. Use about one towel per panel or section, constantly turning and flipping to a new side till all sides are soiled. Discard towel into another bucket or bag to be cleaned later. Never return a dirty towel to the bucket of fresh towels and solution.
5. Dry section with Bead Maker or your choice of drying aid and a drying towel.
6. Repeat 3-5 till the entire car is done and all towels are used.
7. Use this same process on the wheels but with wheel towels instead of your nice paint towels.
Here's a good video Matt did: ONR RINSELESS WASH