What year Roadster? At some point (after 2005) the stub axles changed from one (lower) grease point each side to two.
When I changed the pins on my 2005 Roadster, somebody had added upper lube bolts (the top fixing with the grease nipple), but the kingpins were not drilled. The replacement pins had a drilling down the centre with a very fine feed into the stub axle cavity.
Take the nipple out and check with a length of wire if you have the drilling down the centre of the pin.
Don't worry too much because the lower grease nipple is sufficient on some cars.
