Why don't car manufacturers use FRP bodies instead of metal?

[jmex]

hello,

I know it may sound weird but why not? WHy automobile companies don't go for FRP body instead of metal. It has many advantages over metal. So why not?

 

[Highspeed]

Can't say why not for a specific FRP you may have in mind (you do mean fiber-reinforced plastics?), but plastic body parts are used on many vehicles. Temp range, impact strength, material strength, material cost, and repairability are all factors. You also need to pass crash testing, which can require an inner structure inside the FRP (with exceptions), which can negate any savings from using FRP and/or complicate manufacturing. $ and assembly concerns are big factors for high-volume automakers.