problematic video quality in Elph 100 HS

[MikenOH]

hello all, first post.

I recently purchased an elph 100 HS to replace an A540 that I had for many years. I've been using the A540 for in car video--mounted on a roll bar, and it worked well in that role, but had limited memory and would only record 1 Gb total video per recording. I picked up the Elph since it would take a 16Gb card and would do higher resolution, but the video quality is very poor when recording in the car. I';ve tried it in auto and manual modes, IS on and off and different resolutions but the main problem is that is doesn't seem to be able to stay in focus at speed, where the A540 never had much of a problem.

I'm not sure how to proceed with this and wonder if this camera is just not up to the job. would appreciate any suggestions.