Many parts of the country have experienced 4 to 4.5% rent growth and 3% vacancy but it has been for the past 12 to 18 months.Historically looking at cycles an data that figure is not sustainable long term.

The bigger counties usually have a process to get all of their data and then you can filter and massage it for your needs so that you can identify all mobile homes on land (the same owner for the land and the mobile home) under 1 acre and homes less than 10 years old, for example.  

The state Department of Environmental Quality and the Oregon Health Authority plan to announce that DEQ data indicate a monthly average of 49 times the state air-safety benchmark level for the neurotoxin and carcinogen cadmium, and 159 times DEQ's air-safety goal for the carcinogen arsenic."

Also checkout Magic Leap and Meta AR.

From this data, you can utilize a website bestplaces.net that will give you a breakdown of the percentage of homes that sold, in various price ranges, for a given zip code.

Most of the data is very local.  

You will need to use other data/info to help gather insights to this vinyl situation.  

I went walking for dollars intending to send direct mail, and I actually met a few neighbors that turned into a couple leads and a few good stories.

Appraisals have a tendency to come in low due to using historical data, a trend which is exacerbated in an ascending market - plus, no appraiser will ever get fired for tanking a deal with a low appraisal, only the opposite.

I use my subscription to the AirDNA investment explorer for market data and would be happy to share some insight.