My car sits there for a while the the garage...sometimes up to 3 months at a time. The suspension is under load. Could I buy four bottle jacks and place them under the subframe and lift the tires 1/2" off the ground just to reduce the tension in the suspension? Would four 2-ton bottle jacks be able to stay under a hydraulic load for three months or will a seal burst and lower one corner of the car? They advertise them locally for $15 each...probably the same quality as a Harbor Freight product. The other brand is $60 per jack.

Thousands of cars and trucks sit for extended periods. I wouldn't loose any sleep over it.

My car sits all winter and most of the summer, shhhh in the garage covered up. Lifting it and an un sprung suspension does more harm then good. Back in the day cars were lifted so bias ply tires weren't flat spotted, not a real problem with modern radials. Cars are parked on the street all the time and no problems. Be more concerned with rodents and covering the car and gas contamination.

Always indoors, always under a cover. Bought some tire covers and put them on recently. I have moth balls hanging around the suspension because mice apparently hate the smell along with some rodent killer yummies underneath the car