Oh, dear. A dreadful transcontinental deejay battle's been a-brewing. It's over that song, " 'Liz'beth Taylor's Thighs." (Based loosely and unkindly on "Bette Davis Eyes." A disc of "Thighs" has them all rolling in the aisles in Detroit.) Accepting bows: Detroit deejay Dick Purtan, and a pal of his who wrote the lyrics. Also accepting bows: Our very own deejay Howard Stern, the wild man of DC-101. He says the ditty was composed by him, on the air, right here, with Input from the Audience -- last March. Ear, which adores Investigation, dug and dug. Turns out, finally, that each darling deejay has completely different words to the song. Our local version is a tad primitif. (Ear will merely mention "chows down like a hog . . . runs round like a dog," and hastily move on.) In Detroit, au contraire, the libretto has more je ne sais quoi: ("It says 'Goodyear' on her side . . . When you see her you can't please 'er/Til you show her to your freezer.") Great minds think more or less alike, darlings. Ear doesn't know whether to pop with pride, cringe with shame, or go on a diet and solicit funds for its next campaign. Stay tuned.