1) That website has only a single page!
2) $695 is in USD right? That's over RM2k!
3) Lead acid batteries last only 1 to 3 years in cars. If you do deep/full discharge, the lifespan will be shortened.
4) 110V output
5) If somebody sells solar cells that mounts to my car roof (or I can just put at the read window), and powers a cooler, it would be great. The stronger the sun, the cooler the interior of the car gets!