My mother organized a trip to LA/Disneyland in April for my son's birthday and I am going with them. Unfortunately, she has had some health issues and spending a full day at Disneyland at this time doesn't seem like a wise idea (truth be told he wasn't really excited about Disneyland as he is focused on Legoland in May). We will stay in Beverly Hills and my mother will shop. Renting a car is not an option, as my mother doesn't trust me to drive in LA

. I don't mind as she is the worst back seat driver even though she hasn't driven in almost 40 years! Neither my son nor I are interested in shopping so I am wondering what we can do (we are happy to take cabs). I have looked at the other threads on this forum and also on the web but haven't found anything that sounds terribly exciting, other than the Whale Watching excursions which sound great.
He loves trains and aviation, and I think I will definitely take him to Union Station. He loves to "joy ride" on trains. Is there are particular route we should take that is scenic?
Also, are there any bowling alleys or fun movie theaters in Beverly Hills?
Finally, is Santa Monica Pier "worth it"? In other words, is it a lot like Pier 39 in SF? If yes, we will skip it.
Thankfully he's an easygoing kid, and he will probably be happy just to be in another city, but I would like to make this trip special for him.
I appreciate your input.