Small brake pads

[Giulio Dora]

Had new discs and pads fitted to my rc300h at lexus garage and when I got home noticed pads only covered the middle of the disc have they fitted wrong pads. 

[Linas.P]

I kind of doubt it, RC300h has funny little brakes behind those massive wheels. 

[J Henderson]

2019 car will have the much bigger 4-piston calipers and 355mm discs though.

Was it front of rear that was changed?

Regardless, it's possible and normal for the inside portion of the disc, closest to the hub, not to be used by the pads. Maybe an inch or so, but they should definitely contact the remainder of the surface apart from a few mm at the very outside edge.

[NemesisUK]

2 hours ago, Linas.P said:

I kind of doubt it, RC300h has funny little brakes behind those massive wheels. 

Fronts on the facelift are much bigger than the initial RC300h offering plus the discs are of the 'floating' type.

[Sonu]

The 14" F-Sport brakes require different pad. Even though the standard 4 pot caliper pads will fit in the larger calipers. The shape, more importantly the surface area of the friction material, is slightly different. Here is a picture of the two from an online seller:

Standard Caliper

F-Sport Caliper