The Cars “Just What I Needed” ~ A Question

Does anybody know how Roy Thomas Baker produced the thick percussive rhythm guitar sound in the intro of Just What I Needed? 

Seriously?  That's all it was?  That's too simple.  I thought for sure there was going to be a series of processors to get a sound that chunky.

From an interview in Guitar Magazine.
So many of those songs—“Just What I Needed,” “My Best Friend’s Girl,” “Good Times Roll”—are now guitar-rock classics. What was your setup in the studio?
I only had a few guitars at that point. Because we hadn’t really made any serious money or anything. My main guitar was a ’77 Les Paul Standard that I bought at Manny’s on 48th Street [in New York City]. And I had a Fender Telecaster that had a Bartolini [Hi-A mini-humbucker] pickup in the neck position. I also had a Martin D-35, which you can barely hear on the record, but it’s there a little bit on “All Mixed Up.” And I had two effects. [laughs] That original Roland Chorus Ensemble, the grey metal one, and a Morley Echo-Volume for delay. And that was it. That was my whole arsenal!
 
He doesn't get into recording techniques in the interview, but did state that he was ill when they arrived in London to do the album, and did all of his tracks in a day and half. The whole album was recorded pretty quickly, as they had been playing all the songs live for over a year.

The Cars' Heartbeat City was the first cassette I bought with my own money.
I'm off now to give it another listen (but not on cassette).  Thanks for reminding me of these classics!