Could you elaborate on that solar cell setup? Where can I buy one?

This one will keep a charged battery topped up, but does not put out
enough to charge a flat battery:

https://www.harborfreight.com/15-wat...ger-62449.html

Thank you for your prompt response. While I'm excited about the prospect
of using a solar panel to maintain a trickle charge, the solar solutions
I've come across so far have problems for my usage:

1.) My cigarette lighter outlet doesn't stay on after the ignition is
turned off, so my only recourse is to permanently connect the solar
panel to the battery posts.

2.) The alligator clips for the battery posts are too obtrusive and
would interfere with my current battery post connectors. There needs to
be a solar trickle charger with better integrated battery connectors.

3.) The instructions to these devices state that in order to prevent
damage to the trickle charger, it's supposed to be disconnected before
starting the car and while driving. So how am I supposed to disconnect
it from the battery before starting the car? Others have said that it
works fine while starting the car.

I use one on a car that sits a lot where there is no power outlet to
run a conventional battery tender and it works well.