Replacing broken coil springs

Needing to replace a broken rear coil spring, I am unsure which springs

were standard on this car. 

When I bought the car 13 years ago I recall being told that it was fitted with

Bilstein shockers (they are yellow).

If anyone can tell me which springs to buy (x2) I would be most grateful.

Also does this mean that my car had been lowered from the typically 

high riding look? It doesn’t particularly look like it.

 

The sport package included Bilstein suspension but this does look like a minefield particularly with the rears.

Take a look at this and specifically the last paragraph.

I would do as they advise and then it becomes MX5Parts responsibility, assuming they can supply.