Should I Repair My Car Before Selling?

Why repairs usually cost you more than they return

A dealer works backwards. They look at what your car will be worth once it's cleaned up and ready to sell, subtract what it will cost them to get it there, subtract their margin, and what's left is the offer.

The part that catches owners out is “what it will cost them”. A dealer buys parts on trade accounts and either has a workshop in-house or a rate with one. You walk into a local mechanic and pay counter price plus retail labour.

Say a job is quoted at $900 at your local workshop and the dealer can have it done for roughly half that. Paying the $900 yourself only buys back the dealer's number, not yours. The difference is gone.

There's a second problem. Dealers price in bands, off what the market is paying for that model, year and kilometres. A tidy 2019 Corolla with fresh brakes and a tidy 2019 Corolla with brakes at half life land in the same band. The fresh brakes get noticed. They rarely move the number.

What is worth doing

Everything here is cheap, quick or free. It works because it changes what the car looks like in photos and how it feels when someone opens the door.

• A proper wash and detail. Not a servo vacuum — a real go at it: wheels, door shuts, glass inside and out, dash and vents, seats, carpets and the boot. A Saturday morning or a couple of hundred dollars, and it's the one spend that reliably pays.
• Clear photos in flat light on a plain background. Free. Weak photos get cautious offers, because the dealer is guessing what the paint actually looks like.
• Replacing a blown globe. Headlight, brake light, number plate light, a dead bulb in the dash. A few dollars each, and a dead light reads as a neglected car.
• Topping up fluids. Oil, coolant, washer bottle. A dipstick sitting on minimum at an inspection sets the tone for everything that follows.
• Getting your junk out. The kid's seat you're keeping, the boot full of tools, the toll tag, the glovebox stuffed with paperwork.
• Finding the second key. Worth real money, this one. A missing key means the dealer has to cut and program a replacement, and modern keys are not cheap. Turn the house over before you write it off.
• A windscreen chip repair, if your insurer covers chips with no excess. Free to you, and a chip that's still small is a chip that hasn't spread into a crack.
• A logbook stamp — but only if a service is genuinely due now, or due within a few hundred kilometres. Servicing a car that was done last month adds nothing.

What is not worth doing

Every item here is something owners do with good intentions and lose money on.

• New tyres. The most common mistake there is. Tyres are the thing dealers buy best — they fit them constantly, at trade. Four new tyres cost you retail and lift the offer by a fraction of that, if at all. Worn tyres are a deduction; new tyres are rarely a bonus.
• Panel and paint on a dent or a scrape. Panel work is expensive at retail and cheap inside a dealer's supply chain, and a repaired panel that doesn't quite match is worse than the original dent.
• Major mechanical work — a clutch, a gearbox, an aircon compressor, a head gasket. The repair will cost you more than it shifts the offer. Describe the fault and let dealers price it in.
• A full respray. It almost never pays, and it works against you: a respray on a car that didn't obviously need one makes every buyer wonder what's underneath it.
• Aftermarket accessories fitted to “add value”. A bullbar, bigger wheels, a stereo, a lift kit. Some buyers want them and most don't, so modifications narrow the pool of dealers who'll bid rather than widen it.
• An expensive paint correction on a rough car. A cut and polish is worthwhile on a straight car with light swirls. On a 240,000 km ute with faded clear coat, you're polishing money away.

The grey area: big faults, warning lights and worn tyres

Some jobs sit in the middle, where the answer depends on the car and the size of the number. These are the ones where disclosure usually beats repair.

• An overdue timing belt. On a belt-driven engine this is a genuine cost and dealers know the interval for the model. Doing it at retail rarely returns the money — but it does need to be on the table. Say plainly that it's due or overdue and let dealers factor it in.
• A warning light. Get it scanned before you decide anything. A code read is cheap and sometimes free, and there's a world of difference between describing an oxygen sensor and describing something inside the transmission. A light you can name is a small deduction. A light you can't name gets priced as the worst thing it could be.
• Tyres down near the wear indicators. Not worth replacing — but if one is visibly worse than the rest, or there's cord showing, say so. Roadworthy and inspection requirements vary by state and territory, so check your state road authority if you need to know where your car stands.
• A tired battery. Borderline, but cheap. If the car is slow to crank on a cold morning, it's a small spend that stops the inspection starting badly.

Why disclosure beats repair

Any offer made before anyone has seen the car is priced off your description. Dealers are working from photos, kilometres and what you tell them. That's the arrangement.

If your description is accurate, the number holds when the car is finally in front of them. If it isn't, they find the fault at the inspection — and they do find it — and the price moves on the day, after you've already knocked back the other offers. That's the real cost of hiding something: you end up renegotiating alone instead of choosing between competing offers.

Disclosing feels like it should cost you, and sometimes it does: a known fault gets priced in. But the number you were quoted already includes it, so it's the number you actually walk away with. Dealers would far rather buy a car with a described fault than one that surprised them.

A quick test before you spend a dollar

So when you're weighing up whether to repair your car before selling, run it through this in order.

1. Get the job quoted in writing, so you're working off a real number instead of a guess.
2. Ask whether the fault actually stops the car being sold, or just makes it less tidy. Almost everything is the second one.
3. Describe the car honestly, fault and all, and get offers on it as it sits.
4. Compare those offers against the quote. If the repair costs more than the gap it would close — and it nearly always does — don't do it.