I don't know why exactly your friend asked if you have a car but there are some business that required you to have car, it package you and your business to your clients. If that's why he was asking an feels there is a need, then he is right but if they are asking because they know you are doing well financially then they don't know what financial brilliant is about, they afr financially ignorant and they want to sink you to their own hole of no return, don't think about their questions.
I can be wealthy and doing well but it doesn't necessarily mean I have to copy another person lifestyle or what other people thinks about wealth. When I was struggling to put things in order and make my investment successfully, there wasn't anyone and nobody was there with any suggestions to make it successful. Now that you are doing well, they now think they have a say in what you are going to do, then that's very wrong of them, I will advice you to ignore them.
Liabilities and assets are different. A car can be an asset, if you use it for work, you do not have to even use it FOR work, you can use it to go and comeback from work and that can still be profitable. Because on the long term, you have an item, that pays for itself, since you already had to spend some money to go to your work anyways, you have to realize that while the car does lose value, that difference is what you should be spending anyway. Math is this, let's say you got a car for 30k, and in 5 years, you sell it back for 20k, it did lose value but inflation happened so it's a bit better etc.
Now you are in 10k loss, correct? If you would have spent 10k on transportation in 5 years, that means you made a profit by having your car. Plus, if you also used it for work, then it automatically becomes asset, like get a pick up truck to carry stuff etc.