It's none of his business.
You have every right to be proud of your success.
Yes, it's probably motivated by sexism as well as common-or-garden jealousy, in his case - he would probably be vile to a more-succesful male neighbour too, but in that case he might just go in for a willy-waving contest, wheras in your case he's all comments and overbearingness.
Don't let him. Just don't let him. When he makes a comment about 'god, new car again?' accept it as a compliment with a smile "Yes, isn't it great? A bonus/reward for all my hard work!" and let him seethe/gawp. DO NOT APOLOGIZE FOR DOING WELL!"
And when he tries to stick his beak in, point out he's being nosy. Eg comment on someone working on your house could be met with a smile and a polite/incredulous "Why do you want to know? Do you want some advice on getting internet installed?"
Rude/passive-aggressive 'advice' can be met with a surprised/polite "Did you mean that to sound so rude?" Or "gosh, that's a rude thing to say." then smile and stare at him and let him flounder in the silence.
I sympathize with people being shirty about women doing well. Some people are shirty about anyone doing well but feel the need to express it more vehemently about women - and the fact that you're single probably means that he finds it harder as he can't point to a male figure in your life who is clearly supporting you. Your very existence is a sign that women are capable, clever, and confident... so if/as he's a sexist bugger, it's driving him bonkers!
Don't let him get to you. Smile, brush off, ignore, and in extreme cases say "why do you want to know?" "That's private and I won't discuss it" or just "What a rude thing to say!" with a surprised laugh.
Screw him, and well done you! :)