I also use moly grease & the last Roadster did 30,000 miles on plastic bushes with no play up to the time it caught fire...
I do mine about every 1000 miles.
Neil, the first time I greased the suspension on my new Roadster I thought it must be a candid camera stunt! I kept pumping but nothing came out. I looked for a pile of grease on the floor: nothing. Then eventually, some came out. I don't reckon the factory put much in...
After that, the suspension & steering were much better, so don't give up on the grease gun!
Ian