Careful cleaning of accessible engine-bay surfaces with the right products.
Careful cleaning of accessible engine-bay surfaces with the right products.

The detailer covers the sensitive parts, applies a degreaser to the under-hood surfaces, rinses with low pressure, dries the bay, then dresses hoses and plastic. No high-pressure spray goes into the bay.
It can be, with care. The detailer covers the alternator, fuse box and air intake first, and uses light water rather than a pressure jet. Ask how the detailer protects those parts before the work starts.
Often it is an add-on rather than part of the base price. Ask for it as its own line in the quote so you can see what it adds to the total.
Once or twice a year suits most cars. Cars parked near the coast or driven on dusty inland roads collect deposits faster, so they benefit from the shorter interval.