Hey there Hobie; I did at first, but I did my research. The fangs were only on a black-interior car used in three episodes in Season 4. Can't see the front bumper for the single episode in Season 3 when he was introduced. I still had to modify the bumper anyway, to fill in the Monaco's signal lights, plus add the "tabs" that were sometimes there on either side of the license plate, and sometimes not.
All episodes after the first 3 episodes in S4 were tan-interior vehicles without the fangs. Since I like the tan interior so much more (it's what I vividly remember as a child), I went with that.
Here's the breakdown:
–S3 E14 My Son, Bo Hogg – black interior (no clear view of front bumper)
–S4 E2 Double Dukes – black interior, bumper fangs present
–S4 E4 Coltrane vs. Duke – black interior, bumper fangs present
–S4 E8 10 Million Dollar Sheriff Part 1 – black interior, bumper fangs present
–S4 E12 Cletus Falls in Love – mixed black and tan interiors, NO bumper fangs
–S4 E16 Shine On Hazzard Moon – tan interior, NO bumper fangs
–S4 E24 Miss Tri-Counties – tan interior, NO bumper fangs
–S4 E25 Share and Share Alike – tan interior, NO bumper fangs
–S5 E12 The Treasure of Soggy Marsh – tan interior, NO bumper fangs
–S6 E5 The Boar’s Nest Bears – tan interior, NO bumper fangs
–S6 E14 Dead and Alive – tan interior, NO bumper fangs
–S7 E11 Sittin’ Dukes -- (didn't get around to checking this one)