Preve is not bad. But I am not sure if all the serious bugs issues has been fixed or not. you need to
check the Preve forum to find out if major problem has been fixed or not. Preve is a good car. But I just don't believe the way potong run business. I know now is DRB-HICOM, but we need more time to observe and only will know whether they will do well. In the past, they don't give me good impression. There are many model of car they introduced to market but after a while, they just abandon the car and make the car like a rubbish. For example Juara, Tiara, Savvy, and so on. The consistency is not there. Only time can tell whether they really improve the way they run business.
I owned the Iswara before, the time I bought with RM38k. After 1 or 2 yrs, they dropped the price to RM28k. That make the iswara resale value dropped like a hell. This is something that I lost confident to Proton.
I say NO NO to them even now. I don't want to put myself into trouble again. They have to spend at least 3-5 yrs to gain back the reputation and people's confident to them.
I respect your father. But and then who will drive the car most of the time, if you are the one, and you will pay for it, I suggest you make your own decision. You pay as what you get. Of course must consider whether you are affordable or not.
Prius C is good. But the way UMW give 3 yrs warranty on the RM10k battery really make us like an idiot. They now become blood sucker and we cannot blindly support them. Also, you must understand once the battery spoilt, your prius C cannot run anymore. But for Insight, the car still can run without batter.
Again, test drive the car and find the best for yourself. If you seek advice for your dad, buy car for your dad, then better let him make decision.