A breakdown of all seven BC Racing coilover series: BR, RM, V1, ER, ZX, ZR and HM. Find out which series suits your car and how they differ in specification and purpose.

A breakdown of all seven BC Racing coilover series: BR, RM, V1, ER, ZX, ZR and HM. Find out which series suits your car and how they differ in specification and purpose.

Sparco helmet kits use Peltor standard Nexus wiring, so they work with a Terratrip intercom. Which amplifiers plug straight in, and which need one adaptor lead per seat.

B-G cover the older Subarus and the BRZ. If you run an Impreza or a Legacy your hub comes from MOMO or OMP. Here is the full range and which one fits.

MOMO split the Clio Mk2 hub at the 2001 facelift, so the year on the V5 usually decides it. Which boss kit fits, five steering wheels worth having, and why dish matters more than diameter on this car.

Five steering wheels that suit a BMW E46, the three boss kits that actually fit it, and the two things people get wrong: the airbag, and how much a smaller wheel changes the steering weight.