I buy these types of houses. Are you doing the rehab yourself or hiring it out? If yourself, the $45k may be ok, but if you are hiring it out, you could be underwater fast, even if the major systems are basically in just need of repair but there and sort of ok..
Ignore the trash and vehicles, they take time, but not a big deal. Hire a clean out company and come back in a week. If you can get title to the vehicles you may even be able to sell them for scrap.
Things to look at--roof has growth on it. It may need to be replaced. Also photos of the bathroom shows buckets, trash can and a pot. People who live like the photos show do not leave a pot on the toilet without a reason. Either the toilet needs a pot of water to flush it, or there is a roof leak, which could be drywall replacement in the ceiling and mold to deal with. The trash can with the plastic liner in the tub--why? Roof leak or to wash something or store water? There is no showerhead. Good news--there is tp, so the toilet likely works! Kitchen sink looks like they have a work around for the faucet. But dirt on dishes to the left of the sink shows they did not use water recently. There could be water supply issues to the house or just water fixture issues. Anyway, I would say you should plan on some plumbing issues. And there possibly is a need for a new roof.
Is it on septic? IF so, that can be $20k easy, and it could be bad with the weight of all the cars driving on the leach lines. If on sewer, maybe $1k to $2k for a new line to the sewer, not bad. If you are on septic there, look closely for issues in the yard.
The photo shows that the garage door is not all the way closed and it is crocked. That may indicate that the foundation or the garage slab moved. Whether that is enough movement to be a problem is just a guess with the photos given. You may be able to tell more by looking at the house/garage from the street and also looking at the roof lines.
Kitchen photo shows junk where the frig should be. Does the electrical work for the frige area? Most people, even if they do not cook, do put beverages in the frig. And its not likely they took the frig as the area has stuff in it. Also the range appears to be ancient. I would assume it is not working. Also note the electrical outlets were painted over in green paint in the kitchen. So that leads to an electrical issue concern. To look at that issue further, you can see the fluorescent light bulb box/package in the kitchen and in several rooms you can see the light fixtures attached to the ceiling with dangling cords. Leads me to believe that they may be using these lights with a generator. Is that because they did not pay the electrical bill or because the house has an electrical issue? Were the wires 'recycled' from the walls? It could be $6k+ to rewire a house, plus fixing the drywall and painting.
You definitely need new paint inside and out. The front of the house is not even the same color as the back. You need new flooring and at least some windows, landscaping. I looked for HVAC and would not bet that you have any system for even heat. There was one vent over a door, but I did not see much else, or a hot water heater, nothing for those systems, so do not count on them being present.
Also, often with tax auctions they do not give insurable title for the property. Check on that. They often do not clear utility bills--water, sewer, gas, electrical, so if those attach to the house in that area, check out how much they are to clear. Also, they may not clear a HOA or POA bill if it is in a planned community.
With just the information given I would not expect $45k to cover the possibilities, you have most major systems as possibly in failure or not present. The only way I would go for this property at that price is if I talked to many neighbors and asked them what they know. And do not go on just one neighbor--they may be bidding or have a relative interested or not want an investor to buy it, so ask them all. See what you can find out from them. They may know a lot. When was it last lived in? etc.
This one has so many possible issues---caution!