How to open topic?

I believe you might tried below ways to open topic.
" There is a fuel saving engine oil..."
" I am doing oil business, you should interest to know more.."
" I have a good product to share with you..."
" I am selling a basic necessity product... engine oil."
Now I always ask people question to open topic. Let them help me to answer and open topic.
" Do you and your friend drive car?" Yes
" Every car need to replace car lubricant regularly. Do you agree?" Yes
" Did you get any rebate or benefit when you replace car lubricant?" No
" If you have choice, when you replace car lubricant, you want to pay by your own?
or other people pay for you?" ......... of course other people pay for me, but....
" But can you get such thing thing outside?" No
"Let me share with you how Glopac can do that!"