Historically when does the market bottom in a recession?

Trying to decide when to pull the trigger, and buy to hold for about 12 months.

How much lower can the market realistically get? We are almost back to pre-covid numbers.

Saving up for a Jeep and got 15k put aside but trying to decide wether to just go ahead, and get it now or to buy the dip then buy when the market recovers, and car prices are hopefully lower.