All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu 'alayhi wa sallam, is His slave and Messenger.
It is not permissible to deal with commercial insurance companies either in terms of buying your car insurance from them or investing your money with them, if they provide this service. This is because they do not observe the Shareeah conditions in their transactions. So, they are just like banks that deal with Riba in this regard.
A person should fear Allah and stay away from Riba, as Allah Says (what means): {O you who have believed, fear Allah and give up what remains [due to you] of interest, if you should be believers. And if you do not, then be informed of a war [against you] from Allah and His Messenger.} [Quran 278-279]
The ways to save money and invest it in a permissible investment are so many and the one who searches for them will find them. Even if the profit given by the Riba-based institutions is more, there will be no good in it. Little lawful earnings are far better than what is unlawful even if the latter is much more. Allah Says (what means): {Say, "Not equal are the evil and the good, although the abundance of evil might impress you."} [Quran 5-100]
For more benefit, please refer to Fataawa 361417, 341419, 404938, and 402904.
Allah knows best.