Most resistive loads, like car bulbs, or any small heaters in cars, won't be damaged by inductive spikes. The presence of the resistive load will tend to reduce the inductive spike anyhow.
For example, if you have a relay that takes 100 mA, and you put a 5 W bulb in parallel with it, you'll get about 400 mA in the bulb. When the switch turns the current off, the 400 mA in the bulb can stop instantly. The 100 mA in the relay will continue, but now it can flow backwards in the bulb. 100 mA backwards for 0.01 seconds isn't going to be noticed in a 5 W bulb, so you have no problems with inductive spikes.
Some relays contain a resistor in parallel with the coil to reduce the inductive spike.
Where you can get problems is that a circuit designed to drive a relay at 100 mA may be damaged by 500 mA. Also, on the ignition coils of a car, the circuits rely on the inductive spike to generate the spark. If you put a resistive load in parallel, you will remove the inductive spike, and there will be no sparks and the engine won't run.
For example, if you have a relay that takes 100 mA, and you put a 5 W bulb in parallel with it, you'll get about 400 mA in the bulb. When the switch turns the current off, the 400 mA in the bulb can stop instantly. The 100 mA in the relay will continue, but now it can flow backwards in the bulb. 100 mA backwards for 0.01 seconds isn't going to be noticed in a 5 W bulb, so you have no problems with inductive spikes.
Some relays contain a resistor in parallel with the coil to reduce the inductive spike.
Where you can get problems is that a circuit designed to drive a relay at 100 mA may be damaged by 500 mA. Also, on the ignition coils of a car, the circuits rely on the inductive spike to generate the spark. If you put a resistive load in parallel, you will remove the inductive spike, and there will be no sparks and the engine won't run.