With a freshly painted car back, it must go back together.

What is your preferred method to protect the paint while reassembling a car? Fender covers, soft cloths, tape, plastic covering....?

If it's a 2-stage (aka basecoat/clearcoat) or a catalyzed single-stage, I let 'em sit for a few days before covering anything. Then I use old bath towels over fenders & nose panels. Installing engine, I have some soft blankets and moving pads for firewall & aprons. I'll cover the rockers with bath towels if I'm doing interior work or getting in/out.

The paint has been applied for about a week and change. Thinking some new towels may be best.

I use a nice soft blankie with a fender cover over it.

I have been told by body shop guys that it's smart to do the engine compartment and front suspension reassembly with the front sheet metal off the car.

When I put my mustang interior back in I took my shoes off so I wouldn't scratch the door jamb sills getting in and out every 5 minutes.

If the part is heavy or awkward to hold onto then wait until you have a helper. Just because you can pick up your bumpers by yourself does not mean you can hold them perfectly steady while installing all the hardware.

One time I put a door mirror on a car with week old paint and the plastic base gasket sunk into the clear coat before it was fully cured. I thought it was dry by then and it wasn't. Hardly noticeable so I left it alone, but it does show that it takes paint longer than you think to fully cure.

My friend who is an automotive painter once told me that the paint is not quite cured until the paint smell has gone away. He told me not to put a car cover on my freshly painted car until this was the case.

Not sure about the fender protectors but I would be very careful until the paint smell has gone away.

Nothing, what ever you put on it is going to give a false feeing of security & opens you up for issues. Just don't touch it or drop anything on it, don't lean on it & don't touch it.

The last one I did had shadow mask on the fender tops & it was nerve wracking but I got thru it with no marks/scratches/dents.

NICE Mark!

I might have used a spare bed sheet but didn't really lean over the fenders much at all. You can get 99% of the engine compartment assembled from the inside. I crawled under the car and worked in the engine compartment most of the time. The only things I had to lean over the paint for were filling up the master, installing the heater hoses, radiator exc.

If anyone has a fender cover of this material type, lay something down first like a shower towel, soft blanket, etc. You may be safe in a cooler temp but if it gets hot enough, ... it will etch a pattern of the texture of that cover even on a clear coat that is well over a year old!!

I pulled this pic off the net for a an example

Bed sheets work well for fenders. Shipping blankets work for installing engine and for laying on under the car. Don't forget in the cold months zippers on coats and jeans are a no no. Get rid of your belt buckles as well when doing engine bay work. Even before paint as not to scratch the primer I taped my buttons on my welding coat.

Good Advice on the clothing. The older I get the more I find myself just wearing athletic shorts when I work on my cars in the Summer. I normally wear cargo shorts and often find that I forget I have a phone or something in one of the pockets. I walk fast almost everywhere I go and it never fails that the phone moves around in my pocket enough to swing out far enough to hit a car. I've never done any damage but, I curse myself every time it happens.

I use one of these:
https://www.griotsgarage.com/product/ultra+soft+fender+cover.do?from=Search&cx=0

Super thick and soft, has magnets sewn in on the corners which help it stick to the car without sliding off. If it gets dirty just throw it in the washing machine. Mine has lasted many years and still works great.

I went to Harbor Freight and bought 3 of their 40'x72' packing blankets and a couple of packs of their 1x3 magnets. We sewed pockets for the magnets and put them on the CUDA. They totally protect the front end and total cost was under $20.00. They fit well on A bodies also.
Put your engine in from the bottom saves a lot of grief.
These pics were before we sewed pockets in for the magnets. It worked fine like this too.

Moving blankets always work for me. If you go this route get the heavy ones, not the light duty. They are sold by weight. Various sizes are available too.