Sex Sells Engines?

So, after blogging yesterday about pornography and using loaded words like "sex" and "skin flicks", I couldn't wait to what kinds of ads Google AdSense would serve up on my site.  I knew there'd be nothing hardcore - this is Google - but I wasn't prepared for what I saw.

Three out of the five ads are for engines or engine rebuilding.  After much puzzling, I have two theories, probably both wrong:

• I did say "Pornography Drives Technology"; could the word "drive" lead to ads for engines?
• More interesting, I said that pornography appeals to the same demographic as technology - young men.  But, of course, so does engine rebuilding.  So maybe Google serves engines whenever anyone mentions "sex" - a search engine version of sublimation.

I'd be interested to hear comments from the many of you who understand the AdSense keyword algorithm better I do.