is it leaking air? if not, and as u mentioned, no vibration felt, it should be ok. u could get a new one at the dealer (probably pricey, but new and most likely 1 year warranty from volvo/dealer), or individual (i sold my 16" for 50, had curb rash but otherwise good condition and balanced), or from www.tires.com for $125 (click discount tire direct to your door and select the volvo 850 model and u'll see replica wheels at 16"). this way, u could throw away, no, recycle, the ridiculously small donut spare and put your bent one in the trunk as spare. it should fit...if it doesn't, just take out that little plastic piece that holds the spare in place and put some padding for both cases in there to prevent scratching the face of ur "new" bent spare. get a new tire with ur new wheel (should probably get same time and mounted from tires.com) and u'll have peace of mind cause it won't be as urgent when u do need to use the spare.