On my Hyline rear tire carrier CB mount. I've been able to achieve an SWR of ~1.5 or less without much tuning. From researching before I bought anything(mostly from this forum), I bought a decent unit, good whip w/spring, and good heavy gauge cable.
Had to remove some powder coating to get a good ground. Certainly gave me some peace of mind when wheeling in BFE areas of Colorado and Utah when I had no cell reception... had it set on emergency channel and heard conversations with folks this summer hiking/wheeling that were asking for help and were answered by local park rangers/blm or whoever they were.