Not really but my characters are based on ancient societies, but honestly if you write about one part of the US your not from you practically are writing about a different culture so make sure to study the individual state your researching. The USA is 3.797 million square miles. Each state is the size of a small country Texas is nearly 3 times the size of the UK and slightly over twice as large as the Philippines, so naturally every state is different. Each state has a varying degree of nationalism, food variety, cultures etc each developing their own multiple subcultures. If someone goes to Alabama then goes to Tennessee they'll see a very similar culture from Alabama but also something strikingly different.
Yes, that can be pronounced as 'McDees' but if you spell it McD's people know what your talking about.
most now use dryers to dry clothes but there are poorer areas in the Ghettos of the inner cities and the Mid-west states that can still leave out clothes to dry. And yes most of us have cars but we rarely actually buy them up front but have somewhat cheap payments we make every month for years at a time or we use loans. Technically there are automatic vacuum cleaners but most people still have manual vacuums that are much cheaper.
That's usually the result of our culture but in recent years it can be more common for people at age 20 to not live on their own though it's preferable to alot of families that your out of the house by 18. In some areas it's especially if your the oldest sibling since not only are you always a legal adult by 18 but there would also be more people to take care of.