Originally Posted by fsdork
Originally Posted by Bottom_Feeder
They do a fine job of sealing in your not-totally-clean paint and leaving a nice haze, but it's better than not being washed at all.
I really wish the wax option and undercarriage wash option were not always combined in pretty much every automatic car was out there.
This is exactly my feeling. Thankfully the "silver" tier at my local car wash includes undercarriage wash and no wax/sealant. I would probably spring for the longer undercarriage wash time on the "gold" tier if I could opt out of the wax.
Here in the rust belt with a vehicle treated with one of the many rust prev. products (Krown, FF, Carwell, NH Coatings) we are told to avoid the undercarriage wash, except on the way to get my vehicle treated.