A car transfer cushion looks simple, which is why nobody checks it. It turns on a base, it locks in place, and it wears down quietly. The check is short. The hard part is deciding who does it, who pays for a replacement part, and who writes down what they found.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Start with the ownership list
Write three names next to three parts: the base, the rotating lock, and the seat pad or cover. For each one, name the person who checks it, the person who pays for a replacement, and the person who gets the call when something is wrong. If the cushion belongs to your parent, decide whether replacement parts come from your parent's money, a shared family fund, or your own pocket, and write that down before the first part fails.
What to check each week
Look at the base first. It should sit flat on the car seat with the non-slip feet or suction pads in full contact. Grit or crumbs under the base reduce grip, so lift the cushion and wipe the seat and the base before each use.
Test the rotation lock. The cushion should click into each locked position and stay there when you press down on the edge. If the lock feels loose, catches only some of the time, or lets the cushion drift when someone sits, stop using it and check the manual for the replacement step.
Look at the pivot and the pin. Any visible wear, cracking, or a pin that sits crooked means the part needs replacing before the next transfer. Do not wait for the next appointment to decide.
Check the cover. Tears, flattened foam, and a surface that has become slick all change how the parent sits and slides. A torn cover can also catch on clothing, so patch or replace it instead of leaving it.
Check the seat belt and the car
Make sure the cushion does not lift the seat belt buckle or push the belt across the body in a new way. Check that the car door still closes fully with the cushion in place. Vehicles differ, so the cushion that works in one car may not sit right in another.
Keep a simple log
A log does not need to be fancy. A card in the glovebox or a note on the phone is enough. Record the date of each check, what was found, and what was replaced. The log is what tells you whether a part is wearing out faster than expected, and it gives the manufacturer or a repair shop something concrete if you need help.
If you want to see how this desk separates a claim from a source before you rely on a manufacturer's number, the Sources page explains the approach. Use the manual's own check interval and weight limit as the starting point, not a guess.