solar panal question

I saw a solar panel at a hardware store today. There was a 2w (I think) that sat on your dash to trickle charge you auto battery for $29.00 and a larger one for $79 that said 5w for RVs and boats. Are these of any use?
Cheri

These are only good for maintaining the battery when not in use. I've heard different stories on how well they work. ?????
I have an 75W and it does a great job. I just returned today from a 4 day boondocking trip, one Wal-Mart deep cell. It never got below 3/4 charge. It rained a couple of the days, for a couple hours.

Good Luck

Jack

I thought it might be too good to be true.
Thanks
Cheri