Panels look like left over Hull parts of destroyed Ships.

They appear "near" Stations and inside Asteroid Belts.

A great (and peaceful) Place is the Aaron Halo in the Stanton System.
Simply Quantum towards the Central Celestial Body (aka. Sun) and drop out of Quantum between 21,300,000 km and 19,670,000 km distance from it. Then you'll find yourself inside the Aaron Halo Belt.

To find Panels just fly to your designated Area and Scan (Tab).
One Panel has a Signature Size of 2000.  So if you find a Signature of 8000 it means that there are 4 Panels.
The maximum of Panels are 14 which will have a Signature of 28000.

The Panels you can salvage for RMC aren't fracturable for CM so don't bother.

There are several Scraper Modules on the Market.
Each one has it's ups and downs. 

Decide for yourself, with what Module you want to equip your Salvaging Ship.

Personal Opinion: I use the Abrade Modules in both of my Reclaimer Salvage Seats for they have the best output.

Pros:

• A tool platform that can use multiple different attachments for a line of different roles (Medical, Mining and Cutting)
• Small and Portable
• Occupies a utility slot (leg slot)

Cons:

• Weak Tractoring power, makes cargo loading harder and more difficult
• The labour of switching tools during operation

Price:

• 480 - 610 aUEC + Tractor Tool - 320 aUEC

Availability:

• Every city, Cargo center, Refineries and Outposts special skinned Multi-Tools can be looted.

Overall:

•  A good entry level tool to begin your career in the 'verse, and tap your fingers into various career paths.

Pros:

• Superior strength and range for tractoring and moving cargo or even ships around (anything up to the size of a DRAKE Vulture)
• Tractor travelling is much faster in space with said tool

Cons:

• Occupies a back slot reserved for rifles (as of 3.22 the MaxLift is labelled as a weapon and cannot be pulled out inside an armistice Zone)
• Price Point

Price:

• 19'000 aUEC

Availability:

• Refineries and Cargo Centers, Not found out in loot boxes yet. No special skinned items are known of this tool.

Overall:

• The MaxLift is the superior tool for the common Cargo Hauler and Box Monkey looking to move cargo around at the cost of a rifle slot, it makes it much easier to move and to manipulate objects from much further afar.

Source: RSI Store Page

Measurements:
Length: 33.0m
Width: 16.0m
Height: 9.0m

Size-Class: Small

Mass: 1,145,910 kg

Cargo Capacity: 12 SCU

The Aegis Reclaimer is an industrial salvage ship. Equipped with a reinforced cargo bay, a long-range jump drive and launch pods for unmanned drones, the Reclaimer is an ideal ship for taking advantage of deep space wrecks. Tractor beams, floodlights, scanner options and docking ports round out the tools on this capable, utilitarian spacecraft. The listed Cargo Capacity is only for the dedicated Cargo Room and does not account for the salvaged material capacity which will be detailed later.

Source: RSI Store Page

Measurements:
Length: 155.0 m
Width: 118.0 m
Height: 50.0 m

Size-Class: Large

Mass: 9,500,158 kg