Thanks for all the suggestions, everybody. I'm trying the simplest methods first. I vacuumed thoroughly. Then set off a smaller flea bomb (3 for $10 at Lowe's). The instructions said to seal tight for two hours and then air out for another two hours. When I opened the van doors to air it out, I saw many fleas flying out, getting away as quick as possible. So the flea bomb didn't kill them, at least all of them, but it made them want to leave.
That night, I still felt several bites, but nothing like before. I bought some tea tree shampoo the next day, and shampooed my hair and beard. Read that fleas don't like the smell, but luckily I love it. Then I bombed the van again for a longer period of time, before airing it out. There were a few fleas that flew out the doors when I opened, but not many. And last night I didn't get bit.
I'm going to use the last flea bomb today and then buy 3 more for later use. I'll keep vacuuming each day, too, and continue to use the tea tree shampoo every day. Hopefully this will do it. If not, I'll try some of the other ideas you guys offered.
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