I once read a post about this problem, but now I can't find it. Anyhow, I get messages about an insane number of vehicles being removed, like 80,000 or so. What's the problem here and how do I fix it? In advance, thanks.

The insane overspawnage of vehicles comes from a couple of different game glitches. One is sandwich and ice cream trucks being caught in a loop and thousands of them at a time (offscreen) get generated. Another is performance limos for sims in high level Showtime careers, and although less common it can also happen with other career related limos. A third is when inactive sims are granted free, cheap cars to get around when they don't already have one or seem to have lost access to it, although that one doesn't usually happen in the tens of thousands.

As you have seen, Overwatch will clean up the mess nightly but it can get out of hand in between cleanup runs. The Traffic mod controls the food truck generation much better and has a setting to disallow performance limos (unfortunate but necessary to do for many of us). For other kinds of limos should they still be a problem or are simply unwanted, see Nonamena's No Limos mod at Simlogical. I use her Careers Plus flavor together with Traffic and they work fine together.
http://www.simlogical.com/ContentUpload ... loads/1581

Traffic also has a setting to force inactives to use taxis to get around when they don't have or can't find their own vehicles, thus dramatically reducing the number of discarded free cheap cars left lying around town. The most I see OW cleanup these days on its overnight run is around 3 or 4 vehicles, not tens of thousands.

Don't get me wrong, I'm glad that you are fond of Woohooer. But is there a reason your seemingly unrelated questions keep showing up on the Woohooer mod's message board? I can assure you that the vehicles are not being romantic and breeding with each other.

The mod specific message boards are for reporting issues, bugs, suggestions for the developer and to get help with interpreting uploaded script logs. They don't get nearly as much readership as <a class="wiki_link_ext" href="http://nraas.wikispaces.com/page/messages/Chatterbox" rel="nofollow">Chatterbox</a>, which is really where general inquiries and "how do I do this?" type questions should go, including anything where the specific mod in question is still an unknown.

Sorry, didn't mean to use the wrong chat room. The thing is, I've played this game for years and never had the problems I've mentioned. I then took a break for a few months, came back, and suddenly started having all these problems. Not knowing what caused them, I thought this board might be the best one to address them.

If it's food and ice cream trucks causing the problem, that bug didn't come about until a Patch somewhere along the way (I think). Certainly we needed LN and Pets to have those kinds of trucks anyway, but it was all long ago. If it's the career performance limos, it's possible you didn't have any high ranking inactive Showtime performers in your worlds prior. This one doesn't hit everyone but it hits pretty hard when it does.