I just got used 2020 Prius Prime Limited and I thought it had Lane Trace Assist, but I can not find it the setting. Am I missing something or does this model not come with LTA ? Thanks
The 2020 Prius Prime came with TSS-P which does not come with LTA, just LDA (Lane Departure Alert). You would have to move up to the 2021 Prius Prime which comes with TSS 2.0 which contains LTA.
No. At least not for a reasonable cost. But people have used Comma.ai's Open Pilot on earlier model PP. I don't have one, but do the search you will find comments from people who have installed it.