The June 2004 issue of Cars & Parts magazine has an article on a 58 Bonneville convertible with the Tri Power engine.
I've yet to see a 58 Bonneville in person. I've seen 57 Pontiacs at car shows but never any 58's.
========= Harryface =========
1991 Pontiac Bonneville LE 3800 V6 ( C ), Black/Slate Grey _~_~_~280,596 miles_~_~_
~_~_~_~_U.S.A._~_~_~_~_~_
~~~The Former Fleet ~~~
89 Cavalier Z 24 convertible
78 Holiday 88 coupe
68 LeSabre convertible
73 Impala sedan